As a child, Izuku greatly admired heroes. He wished to be a hero like his idol All Might once he got his Quirk. By the time children his age manifested their powers, however, Izuku still showed no signs of developing any special abilities. Due to that, his mother took him to a doctor from whom he received the fact that he has two joints on his pinky toe. He would never have a Quirk. Later on that same day, Izuku kept watching videos of All Might on his computer and tearfully asked his mother if he could still become a hero. She hugged him and apologized, words that Izuku would remember as not what he wanted to hear.
Even so, Izuku kept aiming to be a hero and to get into U.A. High School. That led him to be constantly bullied and ridiculed by his childhood friend, Katsuki Bakugo, and his classmates, who believed it was impossible for someone without a Quirk to ever become a hero.
Izuku is attending class at Orudera Junior High School while his teacher announces that all students will graduate this year. Katsuki replies that he's not like the other class members, calling them all fodder and that only he is destined to attend U.A., and he alone will surpass All Might. Once his teacher announces Izuku is attempting to get into U.A. as well, Katsuki is shocked and furious. He berates Izuku and uses an Explosion quirk to scare him, claiming that someone who is Quirkless cannot get into U.A. and cannot do anything at all.
After class, Katsuki takes Izuku's hero notebook, burns it and tosses it out the window. Katsuki tells Izuku that Heroes have had stories about them since their early school years, that only he is destined to reach that school and Izuku is just a stepping stone for his greatness. Before leaving class, Katsuki warns Izuku not to apply to U.A. at all. Izuku leaves the classroom to retrieve his notebook and recollects about how he started dreaming about being a hero as well as how he found out about his Quirklessness.
The same day, while walking home, a villain fleeing the scene of a crime encounters Izuku. The villain had apparently escaped All Might earlier in the day. The villain decided that to avoid detection, he should take over Izuku's body. Just as Izuku fell into despair, All Might showed up and saved him. Stunned, Izuku asked for an autograph, but All Might left before he could ask the questions he had on his mind. In an effort to get All Might to stay, he latched on to All Might's leg and hanged on while he launched himself into the air. After a quick struggle they landed safely on a rooftop. Where Izuku asked if he could become a hero without an individuality. Telling All Might that he always wanted to be a hero and save people.
Suddenly All Might's appearance drastically changes to a more skeletic form. All Might reveals to the young man that he was injured in battle five years ago and can only stay in his hero form for a short time. He goes on to tell Izuku that professionals must always put their lives at stake to save the day and thus cannot openly say whether it is possible to be a Hero without a Quirk as it may not be possible. All Might says that if Izuku cares about saving people, he can always go on to become a policeman, as in that way he can be responsible for putting the villains in jail (even though it is ridiculed). He tells Izuku that it is not bad to dream, but warns him not to obscure the facts and then leaves.
Frustrated with the words of his idol, Izuku starts reconsidering his dream of becoming a hero. His thoughts are interrupted as he gets near the scene of a villain attack. Izuku recognizes Katsuki as the victim being possessed by the Sludge Villain that had attacked him earlier and feels guilty that he might have accidentally let the villain escape from All Might's possession. Izuku, having looked at katsuki's pleading eyes, rushes towards the villain, attempting to save Katsuki despite his Quirklessness. As the Sludge Villain prepares to attack Izuku, All Might, inspired by the boy's action, shows up and defeats the villain before Izuku could get hurt.
The Pro Heroes at the scene started berating Izuku for his reckless behavior. Katsuki became mad that he was saved from Izuku, telling him that he wasn't saved by him at all and walking away. All Might appeared and thanked Midoriya for reminding him what it means to be a hero and then explained that what he did was what most top heroes did in their younger days, this made him tell Izuku that he can become a hero as he offered him the chance to become one.
All Might tells Izuku he's worthy to inherit his strength and that he has the power to transfer his Quirk to people. All Might then begins to train him at the Dagobah Municipal Beach Park by moving large pieces of garbage around, such as trucks, large office drawers, various craters, and bookshelves. After 10 months of training, the day of the entrance exam arrives. At six o'clock in the morning, at the last possible second, Izuku moves the final piece of garbage. All Might commends him and cuts off a piece of his hair and gives it to Izuku, who eats it, receiving his first dose, a very small piece of One For All. However, because the entrance exam is so close, Izuku must hurry to the school without getting used to the power.
Izuku arrives at U.A. for the Entrance Exam, excited that he will be able to have a chance at becoming a hero. As he runs forward and trips, Izuku is saved by a girl's Quirk. The girl says she is nervous and asks if he is as well, to which he replies with a nod. The girl wishes him good luck while Izuku stands there awestruck, having talked to a girl for the first time in his life, ven though he actually didn't talk to her. Later, during Present Mic's presentation of the exam, Izuku gets called out by Tenya Iida for his endless mumbling, which he considers improper behavior. As the practical exam is about to start, Izuku gets intimidated by Tenya once again, this time for acting suspicious towards the girl he met before.
During the practical test, Izuku tries to destroy a 1-point robot, but finds himself too afraid to even move. Yuga Aoyama appears and destroys the robot. Izuku realizes that he is running out of time. Suddenly, a huge 0-point robot appears and begins destroying the area. Izuku tries to run away but then he sees the same girl who helped him before on the ground about to be attacked by the 0-point robot. Izuku musters up the courage to fight the robot and, for the first time, uses One For All and attacks the huge robot with a devastating punch which completely destroys it and saves the life of the girl while shocking everyone else.
However, Izuku's bones begin to crack due to having never used it before and begins falling. He tries to use Detroit Smash to land safely, but to no avail. The girl, whose life Izuku saved, uses her Quirk to allow him to land safely. The practical test is declared over, much to Izuku's sadness as he did not get a single point. Recovery Girl then heals his heavy injuries. One week later, Izuku receives a letter that will determine whether he was accepted into U.A. or not. Izuku opens the letter in his room and a screen with All Might on it appears. He apologises for not contacting Izuku earlier and informs him that he will be working as a teacher at U.A.. All Might tells him that he did fine on the written test, but since he scored zero points during the practical test he has failed. However, All Might tells him that because he rescued someone during the practical test, he earned 60 points, meaning he has passed and therefore being accepted into U.A., much to Izuku's joy and happiness.
Izuku, now a student of U.A., talks with his mother before leaving home to his first day at the university. As he arrives at Class 1-A, Izuku witnesses Katsuki and Tenya arguing with each other, much to his frustration. Tenya approaches Izuku and congratulates him on his feat during the Entrance Exam. Right after, Ochaco arrives at the classroom, with her cheerfulness embarassing Izuku. While observing the scene, Katsuki recollects about a skirmish he had with Izuku about the results of the Entrance Exam, with the latter managing to show courage against his longtime bully after being threatened. This is followed by the homeroom teacher, Shota Aizawa, coming into the classroom and explaining to the students about the Quirk Apprehension Test that they must go through.
Shota further explains that whoever gets last place in the test will be expelled from U.A. High, putting massive pressure on Izuku. The students are tested on the power and use of their Quirks through several exercises under Shota's observation, but because of his lack of control over One For All, Izuku is unable to use it in most of the trials, which leads to him performing below the standards set by his classmates. When the time comes for the ball pitch trial, Izuku, left with no choice, tries to throw a ball as far as he can using One For All, but Aizawa stops him by erasing the Quirk, telling the student that, with a Quirk like One For All, Izuku will become a burden by putting himself in danger several times, and that if he doesn't find a way to prevent One For All from massively crippling his own body, Izuku's future as a hero will be put in jeopardy. Shota then allows Izuku a second chance for the pitch trial. Keeping Shota's words in mind, Izuku powers up only the end of one his fingers and launches the ball at a considerable distance.
Dumbfounded by this development, Katsuki menacingly rushes towards Izuku in order to question him about this sudden Quirk, but Shota stops him with his Capturing Weapon before a conflict can start. Izuku, because of his broken finger, underperforms through the remaining tests, eventually getting last place. However, after showing the results of the test, Shota reveals that he lied about the expelling in order to motivate the students to give their all, much to Izuku's shock. While Shota is leaving, he sees All Might, who tells Shota that he was actually planning to expel last place from U.A. All Might then concludes that Shota sees the same potential in Izuku that All Might sees. Shota shrugs off All Might's words, and says that the chance of Izuku becoming a great hero is higher than zero, and that he does not see anything more than that, claiming to expel Izuku if he sees his chance ever fall below that mark. At the end of the day, Izuku is joined by Ochaco and Tenya, with the newly formed trio walking back home together.
As the Heroics class starts, All Might tells all students to wear their Hero Costumes and head to Ground Beta. Izuku reminisces about the time he had to order a costume of his own. It turned out that Izuku's mother had made a costume herself by hand after looking through some of her son's annotations, feeling guilt for not believing Izuku could become a hero and promising to always cheer for her son from now on. Wearing said costume proudly, Izuku stepped into the training field.
Izuku gets teamed up with Ochaco and is tasked to stop a team composed of Katsuki and Tenya from blowing up a fake nuclear bomb. They successfully infiltrate the building and look around the corners to see if anyone was coming, where Katsuki ambushes them. Izuku manages to save Ochaco from Katsuki's attack, but half of his mask is burned off in the process. As Katsuki is about to attack again, Izuku appears before him, grabs his right arm and throws him into the ground, knowing that he would use his right arm to attack. Izuku tells Katsuki that he has analyzed and taken notes (the same notes Katsuki blew up and threw away in the past) on many Heroes including him. He announces that he is no longer the "Deku" who was a loser, but the "Deku" who's vibe is never giving up, much to Katsuki's fury.
Izuku tells Ochaco to go on ahead while he fights Katsuki. He manages to grab Katsuki's leg with the Capture Tape, but Katsuki breaks free using an Explosion. Knowing he's at a disadvantage, Izuku retreats in order to think of a plan and contacts Ochaco to learn about her location for the strategy. Katsuki eventually finds him and attacks Izuku with a great empowered Explosion move provided from his Grenadier Bracers. Izuku survives and calls Katsuki insane for doing that, but a seething Katsuki demands that Izuku use his Quirk.
Izuku and Katsuki continue their fight, with Katsuki overpowering him although Izuku manages to hold his own. Izuku concludes that Katsuki is stronger than he is. Izuku decides to use his Quirk and informs Ochaco to grab onto something. Instead of hitting Katsuki, Izuku aims his Detroit Smash into the ceiling, destroying the fifth floor's ground, but Izuku is forced to take the full brunt of Katsuki's Explosion. Although Izuku was unable to defeat Katsuki, it did distract Tenya long enough for Ochaco to grab the fake Nuclear Bomb, allowing both Izuku and Ochaco to win.
Izuku is then taken away on a stretcher to have his wound attended to by Recovery Girl. After spending most of the day having his wounds healed, Izuku returns to his classroom. As he enters, Izuku is commended by many of his classmates for his performance during the battle trial. Ochaco asks if he is alright, to which he replies that he is fine. Izuku then asks her where Katsuki is. Although many of his classmates try to stop him, Izuku goes to find Katsuki. Izuku finds him and tells him his secret: that he obtained his Quirk from someone else in order to convince him that he had not been deceiving him.
Izuku is confronted by a reporter from the media, asking him questions about All Might, but Izuku makes an excuse to escape from the reporter. In class, Shota Aizawa makes a remark about Izuku's performance in the battle trial and encourages him to work harder. Afterwards, Izuku is elected as Class President after the class votes, much to his shock. In the lunch room, Izuku is unsure if he is the right one for the task, but Tenya assures Izuku that he is. Izuku then learns that Tenya is from a prestigious family of super heroes. As they continue talking, the siren goes off and everyone begins evacuating. After Tenya stops the chaotic evacuation, Izuku returns to class where he decides to step down as Class President and give the position to Tenya, deeming him more worthy of the position than him.
In a flashback, Izuku is seen speaking to All Might telling him that he revealed to Katsuki about the secret of the One For All Quirk. However, All Might isn't angry about it since Katsuki interpreted it as nonsense and tells Izuku to continue keeping the secret to himself and no one else. In the present, Izuku changes into his gym clothes (since his Hero Costume was tattered during his battle with Katsuki in the battle trial) in preparation for the rescue trial. On the way to the USJ, Tsuyu compares Izuku's Quirk to All Might's, although Eijiro Kirishima dismisses Tsuyu's claim since Izuku's Quirk hurts him unlike All Might's Quirk. Class 1-A arrive at the USJ and listen to Thirteen's speech. Izuku applauds Thirteen. Suddenly, villains attack the USJ which shocks Izuku
Izuku is seen evacuating with his class. However, he is suddenly warped away by Kurogiri to the flood area of the Ultimate Space and Jams. In the water, he is then confronted by a fish like villain who prepares to devour him, but Tsuyu saves him and throws him onto a boat along with Minoru. Izuku thanks her for saving him. Izuku wonders about the villains' goal and then decides that their goal now is to fight.
Izuku says that Tsuyu was teleported (along with him and Minoru Mineta) to an area (the flood zone) that allows her to be at full strength and then deduces that the villains do not know what their Quirks are. He then says that although the villains beat them in sheer numbers and experience, the one advantage they do have is the element of surprise (their Quirks as the villains do not know about them). Izuku concocts a plan and after telling Tsuyu and Minoru, Izuku uses Deleware Smash on the water while Minoru throws his sticky substance. The spread out water converges in the center along with Minoru's sticky substance (with the villains being pulled in), causing all the villains in the water to be stuck together by Minoru's Quirk. Izuku then escapes along with Minoru and Tsuyu, with Tsuyu saying that he was impressive.
Izuku says that their priority is to call for help, that they can take the waterside to the exit, but after remembering that Shota is at the central plaza fighting a large group of villains, Izuku decides that they should head to the central plaza and try to be of some assistance to Shota. However, after reaching the central plaza, Izuku is horrified to see Shota's condition after he is defeated by a monstrous villain.
Izuku is surprised to hear Tomura Shigaraki that they are retreating and wonders why they came for nothing. However, this train of thought is quickly interrupted as Tomura attempts to disintegrate Tsuyu. Izuku attempts to save Tsuyu, but Shota uses his last bit of strength to nullify Tomura's Quirk, saving his student. Izuku focuses his attention on Nomu and attacks him, but this time, Izuku doesn't suffer from recoil. However, the attack barely fazes Nomu, who then grabs Izuku's arm, but Tsuyu wraps her tongue around him. Suddenly, All Might appears, much to Izuku's happiness. Izuku is then rescued by All Might along with Minoru and Tsuyu. After seeing All Might in a bad position, Izuku decides to help him, but Katsuki's attack stops him.
Izuku then watches the battle between All Might and Nomu. After Nomu's defeat, Shigaraki and Kurogiri attempt to finish off All Might, but Izuku intervenes their attempt by running in front of All Might to protect him. Izuku's intervention gives the Heroes enough time to reach the U.S.J, forcing Shigaraki and Kurogiri to stop their attempt. After Shigaraki and Kurogiri are dealt with by Thirteen, Izuku is seen on the ground, crying, as he was unable to do anything to help. However, All Might tells him that is not the case; because if Izuku did not intervene, he would have been dead and thanks him for saving his life. Afterwards, Izuku is taken to U.A.'s Nursery to have his injuries attended to.
The next day, Izuku listens to Shota's announcement about U.A. Sports Festival. After end of the fourth period, Izuku and Tenya listen to Ochaco's reason for becoming a heroine and her history, to which Izuku replies that with her Quirk, she would be able to build for free. After the discussion, All Might arrives asking Izuku to have lunch with him. In the resting room, Izuku tells All Might that he is adjusting to his Quirk, which pleases All Might. All Might asks Izuku to show the world at the Sports Festival that he is the next generation's "All Might".
However, Izuku is unsure if he is up to the task; All Might assures Izuku that he is not forcing him and asks him to remember is feelings during his training at the beach park. During the two weeks before the Sports Festival, Izuku trains himself. On the day of the Sports Festival while Class 1-A prepares, Shoto Todoroki approaches Izuku, telling him that he is stronger than him and will defeat him. Izuku admits that Shoto is indeed stronger, but since everyone is giving it their all, Izuku will also give everything he has got. He then walks out to the Sports Festival with his head up high, stating to himself that All Might can retire.
Once the Obstacle Course Race begins, Izuku manages to get through the narrow gate while avoiding Shoto's ice. Izuku sees that there are robots in front of him and decides that now is the time to put his head to use, no longer shaking in fear unlike in the Entrance Exam. Izuku grabs a metal plate and severs a robot's head with it by using the robot's momentum. Izuku passes the Fall, but soon sees that he is far behind. Izuku gets on the metal plate and blasts himself towards the lead using the landmine.
In the lead, Izuku sees that Katsuki and Shoto are on his tail and blows dust in their eyes with the metal plate, stunning them. Izuku crosses the finish line in first place which allowed him to advance to the second event of the Sports Festival, which is a Human Cavalry Battle. Izuku then finds out that he is worth 10 million points for the Human Cavalry Battle, because he got first place on the Race Course, which horrifies him.
Izuku has trouble finding team mates, but then Ochaco decides to team up with him, which makes him happy. Izuku then tries to team up with Tenya as he has great synergy with Ochaco's Quirk but he politely declines, much to Izuku's disappointment. Mei Hatsume decides to team up with Izuku. Izuku decides on a final team member and chooses Fumikage Tokoyami.
The event begins and Izuku's team is attacked by Tetsutetsu's and Toru's teams, but thanks to Mei's gadgets and Fumikage's Dark Shadow they manage to thwart their attacks. The team takes to the air, but they are suddenly attacked by Katsuki. Fumikage uses his Dark Shadow to block Katsuki's attack and the team lands on the ground. Izuku says that they should have an easier time now, but takes those words back when they are confronted by Shoto and his team.
Denki unleashes a large amount of electricity which Fumikage's Dark Shadow protects them from. Izuku and Shoto's team battle with neither team having the advantage. In a surprise twist, Tenya uses his Reciprocating Burst, allowing Shoto to take his 10 million headband in an instant, shocking Izuku. Izuku becomes distressed but thanks to Ochaco's encouragement, Izuku remembers that his teammates fates are in his hands and deicdes to attack Shoto with One For All as a symbol of their unity.
Izuku uses One For All to blow wind pressure at Shoto which distracts Shoto and allows Izuku to take a headband. However, Izuku took the wrong headband and his team fights Shoto's team for the last ten seconds. The event ends and Izuku becomes depressed. Fumikage reveals that he took a 615-point headband during Izuku's scuffle with Shoto which allows his team to move on to the last event. with Izuku crying in happiness. After the lunch break begins, Izuku is seen with Shoto in private in a hallway, with Izuku asking what is it that he wanted to talk about.
Shoto asks whether Izuku is an illegitimate child of All Might or not, but Izuku states that is not the case. Shoto then tells Izuku about him; that he was conceived from a Quirk Marriage so that his father, Endeavor could raise him to be a hero that surpasses All Might; in the past, his mother threw boiling water on him because she despised his left side and that he will surpass Izuku without using his fire power as a way of disavowal-ling his father. Shoto's story leaves Izuku shocked and speechless. Although their goals are different with his goal being trifling compared to Shoto's, Izuku says he cannot let down the people who have helped him get so far and declares that he will defeat Shoto.
The final event is a tournament event and Izuku's opponent in the first round is Hitoshi Shinso. When Hitoshi approaches Izuku, Mashirao warns Izuku not to respond to his provocations. During the recreational events, Mashirao gives Izuku advise on Hitoshi's Quirk. Before the first fight begins, All Might goes to see Izuku and advises him to smile in the face of anxiety and fear. A confident Izuku steps out to the ring to confront Hitoshi. After Hitoshi calls Mashirao an idiot for throwing away the opportunity to participate in the tournament, the fight begins and Izuku, who is angered by Hitoshi's insults, attacks him, but mysteriously stops moving.
Izuku finds himself to be completely immobile, but when Hitoshi orders him to go out of bounds and starts walking towards the exit of the ring. Still conscious, he tries to stop himself but finds that his body is moving on its own. As Izuku is about to reach the out of bounds of the ring, he has a hallucination and sees shadowy figures which causes Izuku to attack himself with One For All, allowing him to break free of Hitoshi's control. Izuku hypothesizes that the people he saw were those who had One For All before him. Izuku ignores Hitoshi's provocations and attacks him. After a brief struggle, Izuku throws Hitoshi over his shoulder and rings out Hitoshi, causing Izuku to move on to the second round.
Immediately afterwards, Izuku asks Hitoshi about his goal, to which Hitoshi states that he wants to end the discrimination against his Quirk by entering the Heroics Department and becoming a Hero. Before leaving, Hitoshi warns Izuku to be weary of him. Izuku then heads to Recovery Girl's infirmary to have his wound attended to. After his wounds are fixed, Izuku tells All Might about the shadowy figures he saw; All Might hypothesizes that the shadowy figures he saw were the imprints of people who had bared the One For All Quirk. All Might advises Izuku to go and watch the next match. Izuku sits next to Tenya and Ochaco who saved a seat for him. When Shoto freezes Hanta, creating a huge ice glacier in the process, Izuku watches in shock and horror. When Shoto unfreezes Hanta with his fire power after winning, Izuku notes that what he saw seemed immensely sad.
Izuku then watches the other matches, writing down notes on his opponents, such as counter strategies. Ochaco sees this and is impressed with him. Izuku visits Ochaco inside the waiting room and offers a strategy against Katsuki. However, Ochaco politely turns down his offer, thanking him for offering a strategy for her, claiming she'll be all right and they'll meet at the final match. Izuku, along with Tenya, go to their seats in the stadium to watch the match.
Tenya asks Izuku what his counter strategy for Katsuki was, to which Izuku replies that the strategy involved striking fast to gain the advantage. Izuku watches the match and becomes worried when Ochaco gets hit by Katsuki's explosions. After Ochaco collapses and is declared the loser of the match, Izuku expresses sadness.
Izuku leaves his seat and walks away. Along the way, he encounters Katsuki and congratulates him on winning his match. Katsuki accuses Izuku of giving Ochaco strategies, but Izuku denies this and boldly states that Ochaco used strategies on her own accord, much to Katsuki's anger. Izuku visits Ochaco to see if she is alright. Wanting to be by herself, Izuku leaves the room and walks to his next match. Suddenly, Izuku runs into Endeavor. Endeavor tells Izuku to give Shoto a good matchup. Before Endeavor leaves, Izuku states that he is not All Might and Shoto is not Endeavor.
The match begins and Izuku prepares to charge. Izuku manages to barely hold off Shoto's ice attacks with One For All wind pressure, but breaks two of his right hand's fingers as a result. However, Shoto is still able to close in on Izuku several times. After seeing Izuku's injuries, Shoto decides to end the match and sends a wave if ice, but Izuku sends a blast of wind pressure against Shoto's ice with his broken right hand, destroying the ice. Izuku knows of Shoto's limit and berates Shoto for only using half of his power to win while everyone else is giving it their all. Izuku clenches his brokenright hand into a and orders Shoto to face him man to man.
An enraged Shoto runs toward Izuku to face him head on, but Shoto's frostbite affects him, allowing Izuku to hit Shoto with an One For All enhanced punch, knocking Shoto down onto the floor and slightly injuring him. However, Izuku is hit by Shoto's ice in the process of punching him. Shoto manages to get back up and launches another wave of ice but Izuku uses One For All's wind pressure to shatter the ice with ease. The battle becomes easier for Izuku due to Shoto's frostbite weakening him. Shoto wonders why Izuku is going so far, to which Izuku replies that he wants to thank the people for helping him get so far and wants to be a super cool Hero like All Might. Izuku once again berates Shoto for using only half of his power and mocks Shoto's disowning goal. Izuku hits Shoto again. After Shoto gets back up, Izuku tells Shoto that the fire power he has is his power and not his father's. Shoto, moved by Izuku's words, activates his fire power and states to Izuku that he too will become a hero, causing Izuku to crack a smile, happy to see his opponent finally giving it his all like himself.
Izuku and Shoto power up for one final clash. Izuku's wind pressure and Shoto's heat blast create a huge shockwave. After the smoke clears, Shoto is still in the ring but Izuku is out of the ring. Izuku's grievous injuries makes him fall to the ground. Thus, Izuku is eliminated from the tournament event. Inside Recovery Girl's room, Izuku asks All Might for his forgiveness since all he wanted to do was help Shoto overcome his misery. All Might tells Izuku that his match was simply an unfortunate outcome but praises Izuku for helping Shoto with his problem, saying that reaching out and helping people with their personal problems is one of the principal qualities of being a Hero, happy that Izuku has such a quality.
Izuku receives surgery from Recovery Girl, which heals his wounds. After the surgery, she warns Izuku to not abuse his Quirk again. Izuku leaves Recovery Girl's room with All Might and they walk down the corridor. Izuku admits to All Might that someone else is better deserving of One For All than him. However, All Might reveals that he too was Quirkless, surprising Izuku. All Might encourages Izuku by saying that only he can truly shine with One For All. Izuku goes to the stadium where Katsuki and Eijiro are battling. Izuku talks with Tenya who tells Izuku about his fight with Ibara and how he won. After Katsuki defeats Eijiro, Tenya leaves for his fight. After watching the fight, he becomes saddened that Tenya lost.
Izuku, along with Ochaco and Tenya, watches the match between Fumikage and Katsuki. Izuku notes that if Katsuki didn't find out about Fumikage's weakness, Fumikage would stand a better chance at winning. After the match between Fumikage and Katsuki ends, Izuku wonders how the match between Katsuki and Shoto will turn out.
Both Izuku and Ochaco agree with Tenya about watching the final match closely for revenge later. Izuku watches the final match between Katsuki and Shoto. During the match, Izuku yells at Shoto to keep fighting.
Izuku watches the closing ceremony of U.A.'s Sports Festival.Tenya told him about what happened to his brother and that he had to leave the Sports Festival; Izuku wishes for Tenya to be safe. After the Sports Festival is finished, the next day at his home during breakfast, Izuku and his mother talk to each other with Izuku saying that she almost had a rougher time than she did. Izuku's mother is happy about Izuku's Quirk although she is at unease about its risky recoil but nevertheless she will keep cheering Izuku on. Izuku decides that he must find a way to control One For All properly. Izuku's mother asks if he wants to watch a recording of U.A.'s Sports Festival, to which Izuku replies that he will later on.
Two days after the Sports Festival, Izuku is on a train to U.A.. While on the train, some of the passengers recognize him from the Sports Festival, acknowledging his prowess. At U.A., Tenya is running and passes by Izuku, telling him that they should be at least 10 minutes earlier for school. After arriving inside, Tenya tells Izuku that he doesn't have to be worried about his older brother as he will be fine and apologizes for causing him unnecessary concern.
In class during the Hero Informatics period, Class 1-A must decide on Hero names. Izuku thinks of using names similar to All Might's name, but he wants to be more original and eventually picks a perfect name. Izuku is the last student to reveal his name; the class asks him if he is sure, to which Izuku replies that he did not like the name but someone came along and changed the meaning of the name, making him happy. Izuku reveals his Hero name to be "Deku". After Class 1-A is finished formulating their Hero names, Izuku is given a list of 40 work places he can choose from so that he can train from one of them.
After the class period, All Might meets Izuku and tells him of a nomination from a person called Gran Torino, the friend of All Might's predecessor. All Might advises Izuku to choose Gran Torino for his workplace training as he will be able to advise Izuku on One For All usage, thus Izuku decides to go to Gran Torino for his training. At the train station, Izuku tells Tenya if he has any problems he can talk to him and Ochaco about it, to which Tenya replies that he will. Izuku arrives at Grain Torino's address and enters his apartment. However, Izuku finds Gran Torino o be a foolish old man and prepares to leave, disappointed. Suddenly, Gran Torino jumps towards the door and tells Izuku that if he wants to learn more about One For All, then he should stay and put his Hero Costume on.
Izuku puts on his Hero costume (which has not only being repaired but redesigned as well). He and Gran Torino have a mock battle, but Izuku isn't able to keep up with Gran Torino's speed. After the mock battle finishes, Gran Torino gives a hint about Izuku's problem with One For All; that he thinks it is special. Izuku ponders about Gran Torino's hint and realizes that Quirks are simply body functions with One For All being no different. Izuku writes this discovery down in his notebook.
During the night on his first day, Izuku steps out of Gran Torino's apartment and goes to an alley in order to test out One For All by thinking of it as a simple body function. Izuku continues his practicing until morning. At breakfast, Izuku ponders why he still cannot gain control over One For All. After a new microwave arrives and Izuku fails to cook the taiyaki properly, Izuku realizes his next problem; that he has only been using One For All in one section of his body and not letting it flow throughout his body. Izuku activates One For All throughout his body and asks Gran Torino to test him.
Izuku battles Gran Torino while One For All flows throughout his body. this time, Izuku is able to keep up with Gran Torino, but Gran Torino decides to get serious and strikes Izuku. After the battle, the elderly Hero notes to himself that Izuku has dramatically changed in such a short space of time and compliments Izuku for being able to graze him (a cut is shown on Gran Torino's face) even though he was using his own power earnestly. Gran Torino states Izuku that he must get used to using One For throughout his body and informs him that they will continue training after breakfast. After breakfast, Izuku continues his training with Gran Torino.
Izuku continues his training in gaining proper control of One For All with Gran Torino for two days. It is the third day at 5:00 PM, Izuku is on the floor injured due to his training. Gran Torino decides to end Izuku's training in One For All, not wanting Izuku to become stale due to fighting him all the time. Izuku protests but Gran Torino denies Izuku's request to continue training in One For All. Gran Torino declares that they will move on to phase two which is workplace experience. Izuku cleans himself up and puts on his Hero costume. Izuku and Gran Torino leave the apartment. Gran Torino and Izuku leave on a train for Shinjuku. The train passes Hosu. On the train, Gran Torino tells Izuku that they will be fighting villains since they appear at night. Suddenly, the train experiences an emergency stop and a Pro Hero comes crashing into the train, much to Izuku's and Gran Torino's shock. Immediately afterward, a creature that looks similar to Nomu appears. Izuku tries to take action, but Gran Torino orders Izuku to stay put. Gran Torino jumps from his seat and slams himself into the Nomu-like creature, smashing the Nomu-like creature and himself out of the train and into the air above Hosu. Izuku goes to check on Gran Torino but sees that a part of Hosu is ablaze. Izuku wonders what is transpiring and starts worrying about Tenya's safety.
Izuku exits the train and starts running towards Hosu. In Hosu, Izuku witnesses the battle between the Pro Heroes and the two Nomu-like creatures. Izuku is surprised that Tenya isn't at the battle and starts pondering. Izuku quickly figures out that Tenya came to Hosu to find and hunt down the Hero Killer Stain. Izuku leaves the battlefield and searches for Tenya. Izuku manages to find Tenya in an alley where he is on the ground injured and Stain is about to kill him. Izuku activates One For All throughout his body, dashes at great speed, and punches Stain in the face, preventing the Hero Killer from finishing off Tenya. Izuku announces his arrival and declares that he came to save Tenya.
Izuku asks Tenya if he can move, but Tenya tells Izuku that he is immobilized. Stain praises Izuku for his efforts and then threatens Izuku. Izuku decides that he must protect Izuku and the injured Pro Hero. Tenya tries to dissuade Izuku from fighting his battle. Izuku puts on a brave face and says that getting involved in other people's business is one of the principal qualities of a Hero, causing Stain to smile. Izuku and Stain begin their battle; Izuku activates One For All Full Cowl and briefly fights Stain. Izuku's enhanced speed manages to allow him to avoid Stain's powerful strikes and attacks Stain from above with 5% Detroit Smash. However, Izuku's move doesn't do anything and Stain immobilizes Izuku with his Quirk. Stain, impressed with Izuku's actions, decides to spare Izuku but prepares to kill both Tenya and the Pro Hero. Izuku yells at Stain to stop but to no avail. Suddenly, two columns of fire and ice attack Stain but he manages to avoid the attack in the nick of time. Shoto reveals himself and tells Izuku that he texted him more information than usual and came running. Izuku is surprised that Shoto showed up.
Izuku asks Shoto why he is here and is shocked that Shoto is using his fire power. Izuku watches Shoto's battle with Stain; Izuku warns Shoto to not let Stain get his blood. Stain jumps into the air and prepares to stab Shoto with his katana. Izuku realizes that he can move and activates One For All Full Cowl. Izuku, using enhanced jumping speed, appears before Stain and grabs him, attempting to throw him onto the ground. The Hero Killer retaliates by knocking Izuku away with his elbow, causing Izuku to fall onto the ground. Izuku informs Shoto that Stain's Quirk allows him to immololize people depending on blood types for a certain amount of time, earning praise from Stain. Izuku and Shoto team up. Izuku attacks but Stain easily strikes Izuku, licks his blood and immobilizes him; Izuku apologizes to Shoto.
Before Stain attacks, Tenya breaks Stain's katana and rescues Shoto; he apologizes to Izuku. As Shoto and Tenya battle Stain, Izuku is able to move again. Izuku and Tenya team up and attack Stain with their enhanced punch and kick respectively 
Stain makes one last ditch attempt to kill Tenya but Shoto attacks Stain with his fire, causing him to loose consciousness. Izuku, Tenya and Shoto remove Stain's weapons. The three along with the injured Pro Hero leave the alley with Stain in tow. Gran Torino appears and berates him for not following his orders. Tenya apologizes to Izuku, although Izuku admits that he should have been more of a friend. Suddenly, the winged Nomu appears and grabs Izuku. Suddenly, Stain awakens, frees himself and kills the winged Nomu as well as saves Izuku. Izuku is shocked at Stain's action.
After Endeavor arrives, Izuku tries to break away from Stain. Stain's bandaged mask falls off and reveals his true face, shocking Izuku. Stain walks forward and declares that the only one who is allowed to kill him is All Might, unleashing a bloody malefic aura in the process. Izuku becomes terrified and unable to move due to the fear. After Stain loses consciousness for the last time, Izuku along with Shoto and Tenya are taken to the Hosu General Hospital to have their wounds treated. The next day at Hosu General Hospital, the Chief of Hosu Police, Tsurugamae Kenji appears to talk to them. Tsurugamae tells Izuku, Shoto and Tenya that the Hero Killer is undergoing treatment. Tsurugamae states that Izuku, Tenya and Shoto must be punished along with their mentors for not being with them. However, Tsurugamae tells them that the event that transpired with Stain will be covered up due to a limited amount of witnesses. Tsurugamae states that Izuku along with Shoto and Tenya have a promising future and thanks them for their heroic actions.
Izuku gets a call from Ochaco who asks him about his injuries, to which Izuku states that he is fine. After the phone call, Tenya tells Izuku that his left hand won't work properly and has decided not to get surgery because he wants his injury to remind him of his mistake at Hosu. Tenya and Izuku resolve to become better Heroes. Izuku along with Tenya laugh with Shoto after Shoto cracks a joke about hands going bad whenever he is around.
At the end of the week, workplace training comes to an end. Outside Gran Torino's apartment, Izuku thanks Gran Torino for looking after him; Izuku praises Gran Torino for his training as it has allowed him to become stronger. Gran Torino advises Izuku to maintain his control and composure when using One For All and to not go over the 5% limit. Izuku wonders why no one in the Hero society knows about him, to which Gran Torino states that he was never interested in the life of a Hero. Before leaving, Izuku tells Gran Torino his Hero name, making Gran Torino smile. Izuku returns to U.A. and in Class 1-A, Tenya states his resolve to become a Hero anew, Izuku smiles. Class 1-A has Foundational Hero Studies next; All Might says that their lesson will be a rescue training race through Playing Ground Gamma (a construction site with many densely packed lanes which makes it look like a labyrinth). Izuku, along with Mashirao, Tenya, Mina and Hanta are the first group that will partake in the rescue training race. The race begins; Izuku activates One For All Full Cowl and begins maneuvering through the construction site with ease; many of Class 1-A are surprised by Izuku's movements. However, Izuku arrives last after slipping. All Might approaches Izuku and is impressed with him; he asks Izuku to meet with him so that he can tell him about One For All's history.
After Foundational Hero Studies is finished, Izuku heads to the boys' locker room to change into his school uniform. While changing, Izuku wonders why All Might was so serious. Afterwards, Izuku meets with All Might in the Break Room. All Might tells Izuku to lock the door and then apologizes to Izuku for not being at his side during the Hosu incident, to which Izuku replies that he doesn't have to apologize. All Might reveals that Izuku's One For All Quirk was not stolen by Stain which is because One For All can only be passed on when the user wishes it. All Might tells Izuku about One For All's origin; originally, a man who was Quirkless was given a power storing Quirk by his evil older brother whose Quirk stole and passed on Quirks. Unbeknownst to the older brother, the younger brother had a Quirk which could transfer, thus the younger brother's transfer Quirk and the power storing Quirk mutated and became One For All. However, the younger brother could not defeat his evil older brother and passed on One For All onto successors until it was strong enough to defeat his older evil brother. Eventually, One For All was passed onto All Might and he used it to defeat the evil older brother. However, the evil older brother has returned, thus Izuku will face him in battle when the time comes..All Might apologizes for giving Izuku so much information. Izuku says that whatever task All Might gives him he will accomplish no matter what as long as All Might is by his side. All Might thanks Izuku. Back in class, Shota reveals that Class 1-A will be going to a forest lodge during the summer break.
One week before the end of term test, Izuku encourages Denki and Mina to do their best because he wants to go to the forest lodge with them. In the lunchroom, Izuku, Tenya, Shoto, Ochaco, Tsuyu and Tooru eat at a table, discussing how they will perform in the end of term test. After Itsuka reprimands Neito, she reveals that the exercise test is a battle simulation fighting against robots like the Entrance Exam. Back in class, Izuku reveals the content of the exercise test to the class, much to Denki and Mina's happiness Katsuki confronts Izuku and states that he will outperform him as well as Shoto before leaving..On the day of the exercise test, Mr. Principal reveals that Class 1-A will be fighting against U.A.'s teachers in their exercise test. Shota says that Izuku and Katsuki will be paired together, much to their shock. Izuku and Katsuki become more surprised to learn that they will be facing All Might in combat for their exercise test. All Might tells the duo to cooperate together to defeat him.
All Might, Izuku, and Katsuki get onto a bus and drive to an uninhabited city where the test exercise will take place. All Might, Izuku, and Katsuki arrive in the city. All Might explains the test exercise: Izuku and Katsuki have two options of winning and passing the test exercise; they must either handcuff All Might or one of them must escape from the battlefield. Izuku and Katsuki have to accomplish either fighting to handcuff their opponent or one of them must escape the battlefield in 30 minutes. Izuku notes that this will test their flight or fight decision skills. All Might puts on super compact weighted bracelets to give himself a handicap. The test exercise begins. However, Katsuki and Izuku are not able to agree on a plan of action and start arguing. Suddenly, All Might throws a punch which devastates the area Izuku and Katsuki are in which causes Izuku to fall down.
Izuku is shocked at the level of All Might's (even though he knows that All Might is handicapped and severely weakened to begin with). Katsuki attacks All Might but isn't able to inflict any damage on him. After blowing Katsuki away, All Might turns his attention to Izuku; Izuku activates One For All Full Cowl and attempts to escape but jumps into Katsuki. All Might prisons Izuku with a guardrail and punches Katsuki in the stomach, greatly injuring him and sending him flying backward. All Might prepares to finish off Katsuki; Katsuki tries to move but to no avail. Suddenly, Izuku activates One For All Full Cowl and breaks free of the guard rail; he then punches Katsuki out of the way and the two escape from All Might. While escaping, Izuku convinces Katsuki to work with him by reminding him that he never gives up on winning. All Might chases after Izuku and Katsuki. Suddenly, Katsuki appears from behind and attacks All Might with an Explosion which distracts All Might. However, one of Katsuki's Grenade Bracers is missing. Suddenly, Izuku appears behind All Might with Katsuki's missing Grenade Bracers equipped on him. Katsuki yells at Izuku to commence his attack; Izuku aims the Grenade Bracer at All Might and releases the trigger. Izuku releases the grenade pin and blasts an immense Explosion at All Might at point blank range. After the Explosion is finished, Izuku and Katsuki dash towards the exit.
However, All Might catches up to Izuku and Katsuki and defeats them, sending Katsuki flying and then using Izuku's body to hit an attacking Katuski ; All Might holds the injured Izuku in the air with his arm.
A minute ago, Izuku and Katsuki are running towards the escape gate after blasting All Might with an immense explosion Suddenly, All Might appears before the two, asking Katsuki what he plans to do after that, shocking Izuku and Katsuki. Before the young heroes can react, All Might disables the duo with his strength. Izuku tries activating One For All Full Cowl, but All Might stops him and throws him onto the ground. All Might decides to finish off Izuku and Katsuki. Suddenly, Katsuki gets up and launches a big explosion against All Might, which distracts the Symbol of Peace. Katsuki decides to distract All Might long enough for Izuku to escape. As Katsuki blocks off All Might, Izuku successfully activates One For All Full Cowl and begins his escape while All Might smashes Katsuki into the ground. Seeing Katsuki in trouble, Izuku rushes back to help and punches All Might in the face, then drags Katsuki with him. Izuku passes through the escape gate along with the unconscious Katsuki in tow, which allows Izuku and Katsuki to pass the practical test.
After Izuku and Katsuki pass the practical exam, All Might carries them to Recovery Girl's tent to be healed. Recovery Girls scolds All Might for not restraining himself during his battle with Izuku and Katsuki. Recovery Girl asks All Might to take Izuku and Katsuki back to U.A. to recover. However, a conscious and healed Izuku requests if he can stay and watch the remaining fights as he would like to observe and analyze the other Pro Heroes and his classmates. Recovery Girl allows Izuku to watch the remaining fights. Izuku along with Recovery Girl watch the remaining fights and comment on them; Izuku is happy to see Minoru pass.
Back at U.A. in class, Izuku tries to help Denki, Mina, Rikidou and Eijiro relax by telling them that something will happen that will still allow them to go to the forest lodge; Denki launches a comical tirade at Izuku for trying to jinx them. Izuku learns that he passed the written exam and will go with all his classmates to the forest lodge which will be a boot camp. The class see that there are many items on the list that they don't have. Tooru suggests that Class 1-A go shopping together in order to get the items they need for the boot camp.The next day, most of Class 1-A (except Katsuki and Shoto) go to the Kiyashi Ward Shopping Mall, a shopping center that caters for all needs. Most of Class 1-A split up to go and buy their specific needs, leaving Ochaco and Izuku alone. Izuku asks Ochaco what she plans on buying and tells her that he plans on buying heavy wrist weights. Ochaco says that she requires bug repellent; however, she begins blushing as soon as she looks at Izuku. The blushing Ochaco runs off on her own shouting bug repellent, leaving Izuku confused and thinking that Ochaco was referring to him as a bug.
Suddenly, a hooded man asks Izuku for his autograph after recognizing him from the Sports Festival. The hooded man admires Izuku for surviving against Stain and living to tell the tale. However, Izuku slowly realizes that the hooded man is a villain he had already met prior to the encounter with Stain after hearing his talk about the USJ. The hooded man reveals himself to be Tomura Shigaraki. However, this time he doesn't have his signature hand on his face; the unmasked Tomura invites Izuku to have tea with him and smiles wickedly.
Tomura continues holding Izuku's neck and tells him to calm down. Tomura tells Izuku that he just wants to have a chat with him and threatens him with disintegration. Izuku warns Tomura that if he attacks him, then a Hero will jump out of the crowd, but Tomura threatens the safety of the crowd. Relenting, Izuku asks Tomura what he wants to talk about.
Izuku and Tomura sit in a plaza. Tomura explains to Izuku that he hates many things. However, what he truly despises above all is the Hero Killer Stain. Izuku tells Tomura that Stain was one of them, but Tomura reveals that Stain was never apart of the Villain Alliance to begin with and that the media and society merely speculated that Stain was a part of the Villain Alliance. Tomura explains that he and Stain have destroyed things in order to change the world but his fame is still undermined; Tomura asks Izuku what the difference is between him and Stain
Izuku answers Tomura's question; Izuku tells Tomura that Stain and him were inspired by All Might and started their journeys thanks to him. Izuku says that Stain didn't destroy because he wanted to, he destroyed in order to try and change the world for the better, according to his ideals. While he doesn't agree with Stain's methods, Izuku respects Stain for living according to his ideals and never giving up on them. Tomura feels exhilarated as he now understands why Stain and Izuku irritate him; its because of All Might. Tomura also understands why he hates the current society as well; because they are all living happily and grinning like All Might. Tomura thanks Izuku for chatting with him.
Suddenly, Ochaco appears and wonders who Izuku is talking to. Tomura lets go if Izuku and begins leaving, warning Izuku to not give chase. However, Izuku asks Tomura what All For One's ultimate goal is. Tomura gives Izuku his answer; that he doesn't know and doesn't care. Disappearing into the crowd, Tomura tells Izuku to take care of himself because the next time they meet, he will kill him. Ochaco calls the Police.
After the Police Force close down the mall, Naomasa Tsukauchi takes Izuku to the Police Station to be questioned by him about the event that transpired. At the Police Station, Naomasa questions Izuku about Tomura and their conversation. Although the information Izuku provides is nothing new, Naomasa thanks
Izuku for the information and praises Izuku for being level headed during his confrontation with Tomura as well as keeping collateral damage to a minimum. While waiting for his mother, Izuku meets with All Might and asks him if there were people he could not save, to which All Might replies yes; All Might says that the Symbol of Peace is hope for Heroes and a deterrent for villains. Izuku's mother arrives, crying about what transpired and Izuku tries to calm her down. Izuku and his mother head home. The next day, Shoto announces that the location for the lodge trip has changed and will be announced on the day. The first semester of U.A. ends and summer break begins.
On the day of the event, Class 1-A boards a bus that will take them to the forest lodge destination. An hour later, Class 1-A's bus stops for a restroom break. However, Class 1-A notes that Class 1-B is not at the rest stop. Suddenly, two females wearing cat-like costumes and a small boy appear; the females excitedly introduce themselves as the professional Hero Team, the Pussycats. Mandalay explains to Class 1-A that they have three hours to traverse to their base. Pixie-bob uses her Quirk to send Class 1-A down to the forest. They encounter a dirt beast; Izuku along with Shoto, Tenya and Katsuki mobilize and destroy the dirt beast.
After Izuku, Tenya, Shoto and Katsuki destroy the dirt beast, Class 1-A begins traversing the Forest of Magic Beasts. Class 1-A arrive at the facility at 5:20 pm in the evening. Pixie-bob admits that she thought they would take longer to get to the facility; Pixie-bob commends Izuku, Tenya, Shoto and Katsuki for taking quick action against one of her Earth Beasts and concludes that they have experienced action against villains. Izuku then asks about the boy, Kota and wonders if one of them is his mother. Mandalay explains to Izuku that Kota is her nephew and asks him to say hello to Class 1-A. Izuku introduces himself to Kota. Suddenly, Kota punches Izuku in his crotch and begins walking away. Tenya goes to check on Izuku and admonishes Kota for his actions. Class 1-A fetch their luggage from the bus, put it in their rooms and head to the dining hall to have dinner. Class 1-A finish eating their dinner and head to the hot springs for a bath. After Kota begins falling, Izuku catches him using One For All Full Cowl.
Izuku brings the unconscious Kouta to the cabin’s office who has passed out from the fear of falling. In the office, Mandalay thanks Izuku for being there to help him. Izuku is surprised that Kota has a jaded view on Heroes. Mandalay explains that there are people in the world who do not like Heroes and if Kouta had a normal upbringing, then he would have grown up to idolize Heroes as well. Pixie-bob arrives and tells Izuku that Kota's parents (who are Mandalay's cousins) were once Heroes. Pixie-bob tells Izuku about Kota's history and after hearing it, Izuku is reminded of his encounter with Tomura and his similar resentments towards Heroes; Izuku begin to understand that not all people have the same opinion. The next day at 5:30 AM, Class 1-A are outside the training camp cabin. Shota greets his students and tells them that they will undergo reinforcement training to strengthen and upgrade their Quirks which will allow Class 1-A to obtain their temporary licenses.
Izuku trains with Tiger. Later that at 4:00 PM, Izuku makes his own curry and while walking back to his class he sees Kota. Izuku follows Kota's footprints and finds him; he offers the curry to Kota after surmising that he didn’t have anything to eat. Kota harshly tells Izuku that he does not want any of his food or company and demands that he leaves. Kota expresses his contempt for the current society of Heroes and Villains; he is angry that they use their Quirks for violence just to show off and blames Quirks for being responsible for many deaths. Izuku tries cheering up Kouta with a story about someone born without a Quirk and could not accept the reality, explaining the moral that it hurts to reject reality. Enraged, Kota orders Izuku to leave and starts threatening him. Izuku apologizes to Kota for not being able to offer any useful advice and leaves the curry on the ground for him. Izuku walks away.
The next day which is the third day of the lodge trip; it is the afternoon and Class 1-A along with Class 1-B are undergoing their Quirk strengthening training. Pixie-bob informs the students that tonight they will be playing a game; a test of courage.
That evening, Class 1-A and 1-B are cooking themselves dinner. Shoto asks Izuku what he wanted to talk to All Might about; Izuku replies that he wanted to talk to him about Kota. Izuku asks Shoto what he can do to help Kota; Shoto advises Izuku to use action than words. Izuku becomes encouraged from hearing Shoto's advice and knows Shoto is correct. Class 1-A and 1-B finish dinner.
During the test of courage later that night, Spinner and Kenji appear in front of the Pussycats and the remainder of Class 1-A; they attack and knockout Pixie-bob. The Pussycats prepare to take action while Izuku realizes that Kota is alone and defenseless.
Mandalei tells the Class 1-A students to leave and orders Tenya to take the lead. As Tenya leads his classmates away, Izuku tells Tenya to go on ahead as he informs Mandalay about the villains' objective.
At the cliff, Izuku appears and saves Kota from Muscular's attack. Izuku concludes that no one can help since his phone is broken and the location he is fighting in is secret. With no other choice, Izuku activates One For All Full Cowl and prepares to fight the villain who murdered Kota's parents.
Izuku prepares to fight Muscular while protecting Kota. The villain takes off his cloak and activates his Quirk. The battle between Izuku and the villain begins. However, Izuku is taken by surprise by Muscular's empowered speed, causing Izuku to be smashed into the rocky wall. Before attacking again, Muscular asks Izuku where Katsuki Bakugo is because targeting Katsuki is his job. The villain attacks again, but Izuku uses his One For All Full Cowl's enhanced speed to evade in the nick of time. Muscular kicks Izuku into the rocky wall again; Izuku lies on the ground injured.
Izuku is shocked at the incredible strength and speed of the villain's Quirk. Izuku uses an enhanced One For All punch but it does nothing; he is knocked back. Muscular considers Izuku an inferior version of him; he torments Izuku for thinking that he can save the child with his hollow strength, mocking Izuku for being unable to back his words up and laughs at the injured Izuku.
Before the villain can attack Kouta, Izuku jumps at Muscular using One For All Full Cowl, telling him that he is the one at fault. Izuku analyzes that the villain's speed surpasses his own and the only slight chance of victory is to close their speed gaps. Izuku punches Muscular with his broken arm, trapping it between the villain's muscle fibers. Muscualr mocks Izuku for thinking that his plan to put them in a position where speed doesn’t matter will work since his inferior strength won't save him. However, Izuku tells Muscular that his job as a Hero is to put his life on the line for the sake of others; with no other choice, Izuku decides to unleash his Quirk's full power: One For All 100%.
Izuku uses One For All 100% against the villain, which blasts Muscular with great force into the cliffside and also partially destroys the cliff due to the great impact. Kouta is sent flying away, but Izuku manages to grab Kouta’s shirt with his mouth and drags him back onto the cliff. After apologizing, Izuku decides that they should quickly escape while the villain is incapacitated. However, Muscular used his Muscle Augmentation to reduce the impact of Izuku's One For All 100% Smash, although Izuku's attack did injure the villain. The villain compliments Izuku for his strength while Izuku is in disbelief that the villain is still conscious even though he used the same output of power as All Might. Izuku tries talking his way out by asking the villains' objective, but he receives no answer from Muscular who puts on his serious eye.
Izuku orders Kota to grab on to him; Izuku uses One For All Full Cowl to jump and run away from the villain. Izuku manages to avoid Muscular's first attack, but barely avoids the villain’s second strike which sends Izuku and Kota tumbling to the cliff again. The heavily injured Izuku thinks that getting back to the facility where Shota could erase the villain’s Quirk is a good plan, but starts to doubt the plan due to Muscular’s speed surpassing his own. Izuku quickly forgets about the plan considering the grave circumstances he is in and decides that he has no choice but to defeat Muscular. Izuku tells Kota to run back to the facility as fast as he can the second he clashes with the villain. Izuku uses 100% Detroit Smash against Muscular which keeps him at bay. Izuku orders Kota to escape while he still can but Muscular considers Izuku's struggle to be in vain. The villain begins overpowering Izuku's attack and begins pushing him into the ground while demanding blood and death. Izuku is barely able to hold back Muscular’s strength and is shoved into the ground by Muscular. Suddenly, Kota blasts water at the villain, demanding that he stop. However, the villain says that he will kill Kota after he is done with Izuku. Furious, Izuku refuses to let the villain kill Kota and begins pushing back the villain, eventually pushing the villain off him. Izuku uses 1.000,000% Delaware Detroit Smash against Muscular, a powerful smack with incredible force that smashes Muscular into the cliff. Muscular's artificial eye pops out and Muscular becomes incapacitated due to the great force of Izuku's attack. Izuku roars with triumph.
After defeating Muscular, Izuku takes Kouta to safety. While running through the forest, Izuku finds Shota and asks him to protect Kouta. Before running off to find Mandalay, Shota asks him to give her a message. Izuku eventually finds Mandalay who is battling Spinner. Izuku activates One For All Full Cowl and shatters Spinner's sword with a leg lunge. Izuku tells Mandalay that Kouta is safe and gives Shota's message for her to telepath. Izuku also tells Mandalay that one of the villains' goals is targeting Katsuki and ask her to tell everyone that. As Izuku sprints to the forest, Kenji tries to stop him only to be interrupted by Spinner's knife.
Izuku runs through the forest, trying to find Katsuki. Out of nowhere, a giant shadow claw is about to attack Izuku; Izuku tries to defend himself, but his adrenaline begins wearing off and starts to feel great pain which stops him from moving. However, Izuku is saved by Mezo. Mezo decides to carry Izuku on his back after seeing his grievous injuries. Mezo explains to Izuku the situation and as a result, Fumikage has lost control over his Quirk.
Izuku and Mezo turn their attention to Fumikage. Struggling against the rampaging Dark Shadow, Fumikage pleads Izuku and Mezo to run away from him otherwise they will die. Izuku watches in shock.
Izuku and Mezo are unable to fight back against the power of the rampaging Dark Shadow. Seeing that their situation is dire, Mezo asks Izuku to decide whether to rescue Katsuki by himself or rescue Fumikage with him. Izuku apologizes to Mezo because he cannot make that decision and says that he has a plan.
Mezo and Izuku arrive to where Katsuki and Shoto are along with Dark Shadow in pursuit, with Mezo asking one of them to make light. Before he can explain further, Moonfish senses Mezo and Izuku’s presence and sends one of his teeth to attack them. The rampaging Dark Shadow uses its enormous claw to crush Moonfish, destroying Moonfish’s teeth and knocking him out. Shoto and Katsuki are surprised at what happened. Izuku’s plan was to lure the rampaging Dark Shadow to their location by creating decoys from Mezo’s Replicant Arms which worked. Izuku is happy to see Katsuki, glad that he doesn’t have to save only one of his classmates and sacrifice the other.
After the rampaging Dark Shadow effortlessly defeats Moonfish, Katsuki and Shoto manage to get close to Fumikage and use their Quirks, which calms down Dark Shadow; Dark Shadow reduces in size and retracts back into Fumikage, allowing Fumikage to return to normal. After Fumikage apologizes, Izuku tells Fumikage that their top priority is to protect Katsuki, who is the target of the villains’. Izuku decides that they should escort Katsuki back to the facility and take a shortcut through the forest to do so. However, Katsuki is angry that he needs protecting and refuses their help. The Bakugo Escort Squad (consisting of Mezo, Shoto, Izuku and Fumikage) begin escorting a begrudging Katsuki back to the facility.
The Bakugo Escort Team travel to the facility and come across Ochaco and Tsuyu. After seeing that Ochaco and Tsuyu are alright, Izuku asks them to join the escort. However, Ochaco and Tsuyu wonder why Katsuki isn’t with them. Mezo, Shoto and Izuku turn around only to find that Fumikage and Katsuki are missing. Suddenly, a masked villain known as Compress appears on a tree branch and reveals that he used his “magic” to take Katsuki by turning him into a marble. The masked magician-like villain states that the Heroes don’t deserve someone of Katsuki’s caliber and notes that Katsuki will shine even brighter on the villains’ side. Izuku demands that he give Katsuki back.
Shoto attempts to stop Mr. Compress with ice, but Compress's speed allows him to avoid Shoto's attacks. Mr. Compress also reveals that he captured Fumikage due to his great power, much to Izuku's anger. Compress begins escaping. Izuku refuses to give up and hatches a plan to save Fumikage and Katsuki that involves them flying towards Mr Compress. Izuku insists that he goes along which convinces Ochaco and Shoto. They execute the plan; Tsuyu wraps her tongue around Izuku, Mezo and Shoto while Ochaco uses her Quirk to make them weightless. Tsuyu throws the weightless Izuku, Mezo and Shoto towards the Compress. The three fly at Compress at high speed and reach him. Ochaco deactivates her Quirk, causing them to land on Compress and smash him onto the ground at the villains' rendezvous point. Izuku, Shoto and Mezo see that they are right in front of Dabi, Himiko and Twice.
Dabi launches his flames, which hits Izuku and injures his arm. Himiko decides to fight and attacks Izuku, telling him her name and thinks that he should bleed more. Mezo smacks Himiko off Izuku while Shoto deals with Twice. When Mr Compress finds that his pocket is empty, Mezo reveals that he took the marbles Fumikage and Katsuki from Mr Compress, much to Izuku's happiness.
As Izuku and Shoto prepare to backup Mezo, Kurogiri arrives and blocks their path. Mr. Compress reveals that the real marbles are in his mouth, causing Izuku to chase after Mr Compress. Suddenly, Mr Compress is hit by Yuga's Navel Laser, causing him to spit out the marbles. Izuku, Mezo and Shoto rush to grab the marbles, although Izuku starts succumbing to his injuries which causes him to fall to the ground. Mezo grabs the marble containing Fumikage, thus saving him. Shoto is almost in reach of the marble containing Katsuki and nearly grabs it, but Dabi snatches it away before Shoto can grab it.
Mr Compress deactivates his Quirk which frees Fumikage and Katsuki. Dabi and Mr Compress begin teleporting away along with Katsuki. Before teleporting with the villains while Izuku desperately tries running to save him, Katsuki tells Izuku to stay away. Dabi, Mr Compress and the captured Katsuki successfully teleport away. Izuku howls in grief due to being unable to save Katsuki.
Two days later at a hospital near the training camp, Izuku is recovering from his grievous injuries as a result of his battle with Muscular. Class 1-A arrive to see Izuku; Izuku is depressed about his failure and the fact that his Quirk amounted to nothing when he needed it the most. However, Eijiro states that Izuku can fix his mistake thanks to Momo planting a tracking device on one of the villains.
However, most of Class 1-A are against the plan. A doctor enters and asks Class 1-A to leave so that he can speak to Izuku privately. As Class 1-A leave the room, Eijiro tells Izuku that they talked with Momo yesterday and have decided that they will rescue Katsuki tonight, inviting him to join them. After Eijiro leaves, the doctor informs him that although his arms are healed, his ligaments are deteriorating and should he gain the same injury twice he will never move his arms again. The doctor tells Izuku that he is being discharged and hands Izuku a letter from Kouta.
Later that night in front of the hospital, Izuku arrives to see Eijiro and Shoto along with Momo. However, Tenya arrives who is angry that they are about to repeat the same mistake he made at Hosu. Although Izuku understands that breaking the rules is against the law, Tenya punches Izuku in the face for not taking his feelings into consideration; Shoto and Eijiro assure Tenya their rescue will be covert while Momo says that she will ensure that there is no combat involved. Izuku tells Tenya that he must save Katsuki. Seeing that they are determined and resolute, Tenya decides to accompany them.
Before leaving to rescue Katsuki, Izuku phones his mother and informs her about his wounds. Izuku’s mother asks if he can stop going to U.A., to which Izuku replies that he is All Might’s successor and as the successor he cannot sit back and relax. The group boards a train to a place called Kamino Ward a place in Yokohama City in the Kanagawa Prefecture. At Kamino Ward, Izuku along with Shoto, Eijiro, Momo and Tenya put on disguises to make infiltration easier as well as to prevent the League of Villains from recognizing them.The disguised group exit the clothing shop and Izuku sees a video clip of the public apology issued by U.A.. After watching the clip, Izuku sees that U.A. are being treated like criminals and that the mood of the people watching has become heavy against U.A.
Izuku along with Eijiro, Shoto, Momo and Tenya continue towards the place that Momo's tracking device is detecting. After waiting for a while near the place, Momo notes that the villains have made no movements and states the possibility of Katsuki not being in the place while Tenya reminds them that if he sees any combat, then he will not hesitate to stop them. Izuku thanks Tenya and starts thinking about their options in "true Midoriya" fashion according to Eijiro and Momo. Afterwards, Momo, Tenya, Shoto, Eijiro and Izuku prepare to infiltrate the supposed League of Villains’ hideout.
Izuku along with the group go to the back of the hideout and see a window. Izuku stands on Shoto's shoulders to see what is inside. After Eijiro sees the inside with his night-vision goggles, he hands them over to Izuku. Izuku looks inside and sees that there are Nomus, confirming that the hideout is actually a warehouse. Suddenly, Mount Lady destroys the front of the warehouse which shocks Izuku.
Seeing that the Pro Heroes are at the warehouse, Izuku and the group assume that All Might is with Katsuki as they are speaking. Izuku and the group decide to head home. Suddenly, the entire warehouse is completely destroyed along with the surrounding area being significantly damaged. The man's aura above them utterly terrifies Izuku, Eijiro and Shoto. Izuku starts to realize who the man above them is since All Might told him about All For One; Izuku is in utter disbelief that he must eventually face such a monster in battle.
Izuku is paralyzed by fear and is unable to move. Katsuki has been teleported near the man, which catches Izuku's attention. Izuku quickly hatches a plan to rescue Katsuki but realizes that it will fail due to there being no options of escape. Izuku prepares to move, but Tenya stops him.
As the battle between All Might, Sensei, Katsuki and the League of Villains continue, Izuku knows that they are in a crisis and there are no openings to rescue Katsuki due to All For One's presence and Katsuki being outnumbered by the Vanguard Action Squad. Suddenly, Izuku comes up with an idea. Izuku says that the plan will not involve fighting and that it will enable them to rescue Katsuki and escape. However, the entire plan rests on Eijiro because Katsuki will respond to him due to the friendship they have built up during their time at U.A. Tenya understands that the plan is a gamble but considering the situation there will not be much risk due to All Might's presence.
Izuku puts his plan into action; Izuku and Tenya hold onto Eijiro with Izuku using One For All Full Cowl and Tenya using his Recipro Burst to burst through the wall while Eijiro uses his Hardening to protect himself, Izuku and Tenya. After Izuku, Tenya and Eijiro burst through the wall, Shoto creates an ice ramp; Izuku Tenya and Eijiro jump off Shoto’s ice ramp and head into the sky.
Sensei sees the trio and attempts to attack them, but All Might intervenes by punching Sensei. Katsuki sees the trio while Eijiro yells at Katsuki to take his hand. Tomura tries to take Katsuki, but Katsuki uses his Explosion to launch himself towards Izuku, Tenya and Eijiro. Katsuki grabs Eijiro’s hand and smiles.
Kenji and Spinner launch Mr. Compress into the air, but Mount Lady intercepts him, allowing Izuku along with Eijiro, Tenya and the rescued Katsuki to get away. Izuku, Eijiro, Tenya and Katsuki land on the ground far from the battlefield and begin escaping.
Izuku and his group along with Katsuki escape safely into a crowd. Izuku sees All Might battling All For One on the broadcast screen and screams at him to win. After All Might defeats All For One, Izuku celebrates. After the battle, All Might points to the camera and delivers a message "you're next". The citizens watching take All Might's message as a warning to all villains out there, causing the citizens to praise All Might and start celebrating again. However, Izuku knows what All Might's message truly meant; that his time as Symbol of Peace has come to an end and he (Izuku) is the next successor. Izuku now realizes that All Might's time has truly come to an end and starts crying.
Izuku along with Eijiro, Tenya and Katsuki meet up with Shoto and Momo. They take Katsuki to a Police Station for safety. Afterwards, Izuku says goodbye and heads home. Izuku arrives home and his mother is glad to see that he is safe and sound. Izuku goes to his bedroom and lies on his bed, exhausted from everything that has transpired and wonders if he made the right choice to rescue Katsuki. Later that evening, Izuku receives a message from All Might. Izuku runs out of his home and heads towards All Might’s location.
At the Dagobah Municipal Beach Park, Izuku goes to All Might. However, All Might greets Izuku with a Texas Smash as a part of his scolding. All Might reveals to Izuku that he can no longer use One For All and demonstrates this by entering his Hero form, only to exit it in a split second afterwards. All Might informs Izuku that he is retiring as a Hero since he is in a state where he cannot fight anymore. All Might scolds Izuku for never doing what he is told and for his recklessness in rescuing Katsuki. However, All Might is glad that his recklessness did not get him injured this time and is proud of Izuku for that. All Might hugs Izuku and apologizes for not being a proper mentor towards him, but from now on he will focus solely on Izuku’s development and training. Izuku begins to cry, to which All Might scolds him for again. Izuku now fully understands that the age of All Might has come to an end.
Toshinori visits and enters the Midoriya household, with Izuku and his mother flabbergasted that the Number One Hero has entered their abode. After the three sit down at the table, Toshinori asks Inko for her permission to send Izuku to the U.A. dorms. However, she is against it, much to Izuku's shock since they agreed that he could be relocated to U.A.'s dormitories. She explains that she is worried about her son since his Quirk damages him rather than helps him and is deeply concerned about her son's future as a Pro Hero after witnessing All Might's brutal battle, unable to bear the fact that Izuku will also have to face such bloody battles with no hope possibility of full recovery. Inko states that she has no confidence in U.A and is unable to entrust her son to them.
Izuku tries to convince his mother that his injuries are a result of his inability to control his Quirk, but Inko replies that regardless it is still the responsibility of U.A. to take care of their students which they have not done. Inko understands that she is being a strict parent but the safety of her child is her number one priority and she is fine with Izuku continuing to become a Hero since it is his dream as long as he is in a safe environment, which is why she wants to send Izuku to another school. Although he understands his mother, Izuku wants to continue his dream at U.A. since that is where Toshinori became a Hero.
Izuku runs out of the room while Toshinori understands Izuku's frustration; that it must be painful not being able to study at the same place his idol went to. Izuku returns to the room with a letter in his hand; the letter is a thank you from Kota. Izuku tells his mother that at the training camp, he saved a boy, who hated Quirks and Heroes, from a villain. Izuku understands that he has a long way to go but for a little while, Kota and his thank you letter made him a Hero. Izuku declares that even if he cannot study at U.A., he will still keep dreaming to become a Hero.
Toshinori is shocked that Izuku is willing to continue his dream even though it is not as the same place as his idol; Toshinori is impressed with Izuku's growth and is glad that he is going on his own path instead of following him, his idol. Toshinori transforms into his Hero form and kneels before Izuku and Inko, bowing his head, much to their shock.
All Might apologizes to Inko for his negligence as Izuku's teacher and understands that she is worried about the bloody path of a Hero; All Might asks Inko to allow him to walk together with Izuku down his path so that he does not have a bloody future. The former Symbol of Peace also understands Inko's concerns about the current U.A and tells her that they are reforming their ways. All Might promises that he will nurture and protect Izuku even at the cost of his own life.
Inko is shocked at All Might's resolve, causing her to fall to her knees. Inko states that all she wants is Izuku to be happy and tells All Might that he should never trade his life away for someone else's sake. Inko tells All Might to continue living and that as long as he can protect and nurture Izuku, she will reconsider her decision to not send Izuku to live at U.A. All Might pledges to protect and nurture Izuku while Izuku tells his mother that he will not worry her.
Outside, Toshinori compliments Izuku's mother, telling Izuku that she reminds him of his master. Toshinori leaves and tells Izuku that he will see him at U.A.
Izuku interns under Sir Nighteye.