Enji Todoroki was always overlooked by All Might and viewed as only second best, regardless of his impressive crime solving record. Enji developed an obsession with surpassing All Might, to the point of forcing a Quirk Marriage upon Rei Todoroki in order to conceive a child with a Quirk strong enough to be capable of surpassing All Might.
When he was five years old, Shoto started to receive training from his father because of his Half-Cold Half-Hot Quirk. However, the training was too harsh and forced Shoto to cry and vomit. Rei would try to defend him, but Enji refused to listen and would even hit her in front of Shoto.
His father also prevented Shoto from interacting with his older siblings and Shoto began to despise the training and resented his father for abusing him and his mother.
During these dark times, Rei would always be there to support him. Despite the abuse she suffered, she would still try to encourage Shoto to become a hero. There was a time when they watched a TV special on All Might. He encouraged children to make their powers their own even if they inherited their parents' abilities. In line with All Might's advice, Rei told him that he is not a prisoner of his bloodline, and could use his powers to become what he desires.
However, Rei eventually broke down from all the domestic abuse, finding it painful to look at Shoto's left side because it reminded her of Enji. One day, as she talked with her own mother over the phone about her trauma and recognized that she no longer had the mental stability to raise her son. She was startled by Shoto's sudden appearance at the door, and after seeing Shoto's left side, she snapped and threw boiling water over the boy's face, giving him a burn over his left eye.
Sometime after this incident, Shoto asked his father where his mother was, to which Enji replied that he sent her to the hospital for hurting him. Shoto blamed Enji, saying that everything that happened was his fault. At some point later in his life, Shoto would forget about his mother's supportive words.
The next day of school, All Might gives the class a Basic Hero Training lesson. He announces that the class will take part in combat training and instructs them to suit up in their hero costumes. Shoto is paired up with Mezo Shoji. During Katsuki Bakugo and Izuku Midoriya's fight, Shoto is surprised at Katsuki's cleverness and motor skills in using his explosions.
For the second match, Shoto and Mezo are the Heroes against Mashirao Ojiro and Toru Hagakure as the Villains. He is informed by Mezo of the opposing team's positions and instructs Mezo to go outside of the building. Shoto freezes the entire building and then suddenly appears on the floor where the core is. He says to Mashirao that he can take a step forward, but warns him of the consequences of doing so as the floor is frozen by his doing. With both Toru and Mashirao frozen, Shoto touches the core, winning the battle for Team B.
During their next homeroom class, Class 1-A is instructed to choose a Class President, and Tenya Iida suggests they take it to a vote. Unlike the majority of the class, Shoto does not vote for himself and instead votes for Momo Yaoyorozu. In Hero Basic Training class, Class 1-A is assigned to Rescue Training in an off-campus facility. During the bus ride there, many of the classmates discuss their Quirks while Shoto remains in the back of the bus with his eyes closed. Eijiro Kirishima comments that Shoto's Quirk is perfect for becoming a famous hero.
The class reaches the training facility, Unforeseen Simulation Joint, and are greeted by Space Hero "Thirteen", who built the facility. It was built as a training area for aspiring heroes to practice using their Quirks to save people. However, rescue training is interrupted by the arrival of several villains. While many of his classmates are paralyzed with fear, Shoto surmises that the villains have a Quirk user among their ranks that can jam communications. He figures that the villains have a concrete objective in mind, understanding that no villain would plan this ambush without a scheme in mind.
Shoto tries to evacuate with his class, but they are separated and warped into different simulation zones of the U.S.J. Shoto ends up in the Landslide Zone and immediately freezes the villains waiting for him there. He taunts them, saying they should be ashamed for being easily bested by a child. More villains attack, but Shoto easily counters and incapacitates them as well. He warns the villains that if their bodies remain frozen, they will die. He offers to unfreeze them in exchange for information on their objectives.
One of the fearful thugs tells Shoto they are in the U.S.J. in order to kill All Might. Shoto makes his way to the central plaza to find All Might trapped by Kurogiri and Nomu. Shoto freezes half of Nomu's body to help All Might get free, and boasts that the Symbol of Peace will not die on this day. After getting up, All Might refuses any help from the students, so Shoto stays back and watches in awe of All Might's incredible power as he defeats Nomu.
Shoto believes All Might will handle the rest of the villains as well and decides to stay back, but Izuku Midoriya rushes to help All Might. Just as Kurogiri and Tomura Shigaraki attack, Tenya returns to the U.S.J. with Pro-Heroes as reinforcements.
The villains are forced to retreat, and Shoto gathers outside the facility with his classmates. He overhears Toru talking with Mashirao about the battle in the Landslide Zone. She talks about how amazing Shoto was, but he thinks to himself about how he never even noticed she was there and how he could have accidentally frozen her. Afterward, Shoto and the others return to school.
Two days after the attack on the U.S.J., Shoto and his classmates return to school and are lectured about the importance of the upcoming U.A. Sports Festival during their homeroom class. At lunch, Shoto's interest is piqued when he overhears Ochaco Uraraka and Tenya talking about All Might taking a liking to Izuku.
As the school day ends, Class 1-A is unable to leave their class thanks to the mob of students blocking the exit. The students are from other classes and are there to scope out their competition for the festival. Katsuki makes them all angry with his arrogant comments, putting a target on the backs of the students in Class 1-A.
For the next two weeks, Shoto and his classmates train in order to prepare for the Sports Festival. When the day comes, Shoto and his classmates prepare in their designated waiting area by changing into their P.E. clothes. Shoto approaches Izuku and tells him that despite All Might's interest in Izuku, Shoto believes he is obviously the stronger of the two. He goes on to express his intentions to defeat Izuku in the Sports Festival.
Eijiro tries to diffuse the tension, but Shoto refuses him and reminds everyone that the festival is not a team effort. Before Shoto leaves, Izuku admits that although Shoto is stronger, he will still try his best to come out on top in the festival. Shoto stoically accepts the challenge and leaves the room with the rest of his class to enter the arena.
Once Midnight explains the rules and directs the pledge, the preliminary games begin. The first round is an obstacle race four kilometers around the area. Shoto gets a head start when he freezes the cluttered corridor but is surprised to find that many students were able to avoid his attack. Several giant villain bots then appear to block his path.
Shoto surmises that these are the same bots that students who took the entrance exam had to face. While impressed with the obstacle, Shoto wishes the U.A. faculty could have offered him something more difficult since his father is watching. Shoto proceeds to freeze the robot while it is off balance and run past it as it falls and blocks the way of those behind him in the race.
Keeping his early lead, Shoto easily clears the next obstacle: The Fall. It is a large canyon that must be trekked by crossing tightropes. Shoto freezes a path through the Fall, but notices Katsuki gaining on him. Shoto reaches the final leg of the race: a Mine Field meant to burden those in the lead. He has to walk through the area carefully, allowing Katsuki to catch up to him. Angered, Katsuki states that Shoto issued his declaration of war to the wrong rival and the two start to fight for first place as they run.
Moments later, Shoto watches in bewilderment as Izuku flies towards him and Katsuki after riding the momentum from an explosion he created. Izuku manages to pass them, but Shoto catches up to him quickly by creating an ice path. Shoto realizes this will help others cross the Mine Field, but he has no choice if he wants to win the race. Before he or Katsuki are able to reclaim the lead, Izuku triggers another explosion that momentarily stops them both. Although close behind, Shoto crosses the finish line second after Izuku. Even though he is unhappy about not taking first place, Shoto qualifies for the second event: The Cavalry Battle.
After Midnight explains the rules of the Cavalry Battle, Shoto forms his team with Tenya, Momo and Denki Kaminari. He explains that this is the strongest formation he could think of. After Shoto explains his strategy to his team, Tenya asks if Shoto will use ice and fire to create diversions. As he responds, Shoto looks into the stands at his father. Shoto claims he never uses his left side in battle. Shortly after the Cavalry Battle begins, Team Todoroki confronts Team Midoriya.
Rival teams rush to the scene as well, forcing Shoto to make a move. He orders Denki to electrocute the other teams while using an insulation sheet created by Momo to protect himself. Afterwards, he freezes the opposing teams and takes a few of their headbands. Shota notes that Shoto is adapting his strategy because he was surprised by how many people evaded his attack in the Obstacle Race.
Even though Shoto's team corners Team Midoriya, Izuku has them keep their distance and remain on Shoto's left side. In this position, Shoto is unable to freeze them without hitting his own teammate. With time running low, Tenya uses his Recipro Burst special move, and in an instant Shoto takes Team Midoriya's headband.
Tenya's special move leaves their team immobilized, giving Team Midoriya the chance to try and reclaim the headband. Izuku charges at Shoto with his Quirk, and Shoto instinctively uses the fire from his left arm to try and counter. Izuku uses his Quirk to break Shoto's defense and steal a headband, albeit not the ten million point one because Shoto switched the headbands around to trick Izuku, but he is too busy berating himself for using his left side to boast.
Time continues to run down and Team Bakugo joins the fray. Both Teams Bakugo and Midoriya make one final effort at the ten million points, but time runs out. Although, Shoto does not notice that Fumikage Tokoyami steals the headband off his head. Afterwards, Shoto is angry with himself for using his left side and decides to confront Izuku at the student entrance.
At first, Shoto uses silence to intimidate Izuku and when he finally speaks, says the power that came from Izuku during the Cavalry Battle was the same as All Might's. Then, much to Izuku's shock, Shoto asks if he is All Might's "secret love child". Izuku tries to explain that is not the case, but Shoto figures out that there is a secret connection between the two. Continuing, Shoto say that because he is the son of #2 Hero Endeavor, he has even more reason to defeat Izuku.
Shoto explains to Izuku that Endeavor is obsessed with defeating All Might, and although he was never able to do it, he is still trying to through Shoto. Shoto reveals that he was born out of a Quirk Marriage and explains some of his past. Endeavor used his money to buy out Rei's family to implement a Quirk marriage with the intent of creating a powerful child to surpass All Might. All of Shoto's memories of his mother are of her crying, as well as when she called his left side unbearable and poured boiling water on his face.
Shoto tells Izuku all of this to explain his reason for picking a fight with him: Shoto wishes to reject his father and his left side, and plans to win the Sports Festival using only his right side. As Shoto walks away, Izuku explains his own reasons for wanting to win and then promises to do his best to defeat Shoto.
Later on, Midnight announces the Sports Festival finals will be a one-on-one fighting tournament. Shoto notices that he could face Izuku in the second bracket, and hopes that he wins. During the recreational games, Shoto uses the opportunity to mentally prepare himself.
Following Izuku's match with Hitoshi Shinso, Shoto comments that he figured Izuku would win. On his way to the ring for his match against Hanta Sero, Shoto encounters his father. Enji calls Shoto's behavior disgraceful and says that if he had used his fire, he could have easily crushed the past two events. He goes on to say that Shoto needs to end his childish rebellion and see to his duty to surpass All Might. He calls Shoto his greatest masterpiece, far superior to his siblings.
Shoto only replies that surpassing All Might is all his father ever has to say and declares that he will only use his mother's Quirk to win. His father replies that Shoto will soon discover the limits to that power. Enji's words infuriate Shoto, and he carries this anger with him into the fight.
As the match begins, Hanta nearly throws Shoto out of bounds by wrapping him in tape and swinging him towards the margin line. Shoto fiercely retaliates by freezing Hanta in a humongous pillar of ice and frees himself by breaking through the now frozen tape. Hanta is immobilized and Shoto is declared the winner. The former comments on how Shoto went overboard and Shoto apologizes and explains that he was angry, and uses his left side to melt Hanta out of the ice.
Six matches later, Shoto watches Katsuki's battle with Ochaco closely. Once the first round of matches ends, Shoto takes to the ring and meets his second round opponent: Izuku. As soon as their fight begins, Shoto leads with an ice attack, but Izuku counters with a Delaware Smash. Shoto creates a block of ice behind him to keep from being blown out of bounds, as he expected Izuku to injure himself in order to destroy the ice.
Shoto persistently attacks until Izuku breaks all of the fingers on his left hand. Shoto withstands the smash and creates a tower of ice to run up and close the distance between them. Izuku uses another smash to break the ice steps apart, but Shoto avoids it and nearly freezes Izuku at close range. In order to break the ice that is slowly freezing him, Izuku sacrifices his entire left arm and lets off a full powered smash. Shoto withstands the aftershock of the smash using an ice blockade. While recovering, Shoto notes that this attack from Izuku was significantly more powerful than the previous ones, and that he realizes his opponent is trying to keep him at a distance. Izuku is startled by Shoto's combat awareness, and some viewing fans even comment that Shoto is already stronger than the average Pro-Hero.
Questioning Izuku's durability, Shoto asks if he is already too worn out from defending against the ice. Izuku does not respond and instead notices that Shoto is shaking because of the frost building up on the right side of his body. Shoto apologizes for the intensity of the battle and thanks Izuku for helping him irritate Endeavor by using only ice rather than fire. Understanding that Izuku has no healthy fingers left, Shoto sends an ice attack at him that he expects to finish the match. Shoto is shocked when Izuku declares that he is not finished yet and uses his already broken finger to counter the ice once again.
Shoto asks why Izuku is going so far, to which he replies that Shoto is trembling, pointing out that Shoto's body can only take so much cold because Quirks are physical abilities. He also surmises that Shoto could offset his temperature by using his fire, but knows Shoto refuses to do so. He challenges Shoto to put more effort into the battle, stating that everyone else is giving it their all while Shoto is only using half his power. Izuku provokes Shoto by claiming that he has yet to injure him in this battle, demanding that Shoto use his full strength.
Agitated, Shoto asks Izuku if Endeavor bribed him. He rushes Izuku, albeit much slower than before because of the frost building on his body. Shoto closes in on Izuku, but as soon as he lifts his right foot to attack Izuku strikes him in the torso. Shoto is partially able to freeze Izuku's other arm but is still sent flying away. Shoto recovers and tries to use another ice attack, but it is much slower than the previous ones and Izuku is able to avoid it. They both move into closer quarters and fight in spite of their afflictions.
As Izuku dashes at Shoto, the latter attempts to freeze him. Without any fingers left to use, Izuku pulls back his thumb using his cheek in order to release another smash to blast Shoto away. Shoto asks again why Izuku is putting himself through so much pain, to which his opponent replies that he is prepared to do whatever it takes to become a hero. Izuku headbutts Shoto and challenges him to use his full strength again, telling him to stop screwing around because even if he wants to reject his father, Shoto does not have the right to be the best if he is not prepared to do his best.
Izuku's words make Shoto recall the terrible memories of his past. As more frost covers his body, Shoto remembers him and his mother being abused by Endeavor. As well as a time where he pleaded to his mother about not wanting to become like his father, to which she replied by asking if Shoto still wants to become a hero. Izuku capitalizes and strikes Shoto with another punch, and declares that he will surpass him. While reeling from the attack, Shoto is reminded of his childhood.
Still haunted, Shoto states once again that he will reject his father, but this time Izuku adds that Shoto's Quirk is his own, and not his father's. This invokes one last memory, one that Shoto had long forgotten. He and his mother were sitting down watching a special on TV about All Might, who encouraged all children to use their Quirk's in their own way in spite of inheriting them from their parents. Rei added that Shoto must remember to stay true to himself, that he is not a prisoner of his lineage, and that it was okay to use his power to become whom he wants to be.
Impassioned, Shoto ignites his flames and astounds the entire arena with his display of blazing power. When the flames die down a bit and the ice melts from Shoto's body, he says that now Izuku is the one screwing around for helping his opponent. Shoto adds that just like Izuku, he desires to become a hero one day too. Having freed Shoto from his self-repression, Izuku smiles and comments that Shoto's power is amazing, to which he responds with an affecting smile of his own.
With the battle reaching its climax, Shoto asks why Izuku is grinning in such a hopeless situation and pleads for Izuku not to blame him for what happens next. They both build up in preparation for one final clash. Ken Ishiyama and Midnight decide to step in, fearing one of them might die. Shoto sends a large wave of ice at Izuku, and the latter evades by jumping above it. As he flies towards Shoto, he prepares a full power smash in his healthy arm, and Shoto counterattacks with a powerful fire blast. Just before he uses the fire attack, Shoto thanks Izuku.
Even though Cementoss builds a wall between them, Shoto's fire attack and Izuku's wind pressure create an explosion that destroys the entire fighting ring. The smoke clears, and Izuku is revealed to be unconscious outside the ring. Everyone is taken back by the battle's outcome, and Shoto stands victorious with half his shirt burned off.
Shoto exits the arena and encounters his father in the corridor. He praises Shoto for using his left side but tells him he needs to control it. Enji offers Shoto the chance to become his sidekick after graduation, but Shoto ignores it and reveals he has not rescinded his disavowal of his father. He reveals the only reason he used his left side is that he forgot about Endeavor during that moment completely. As he walks away, Shoto says he remains unsure about his fire power and suggests he may not need Endeavor at all.
Once the second round finishes, Shoto returns to the arena with a new uniform to face off against Tenya. He starts the match by trapping Tenya between two rows of ice. He goes in for the win using another ice attack, but Tenya evades using a standing long jump and activates his Recipro Burst technique in mid-air. Shoto is able to evade Tenya's initial roundhouse kick but falls victim to the subsequent attack thanks to Tenya's blinding speed. Tenya tries to swiftly carry Shoto out of bounds but is stopped suddenly. He realizes that his engines have been frozen, and questions when Shoto did so.
Shoto reveals that it was after getting hit with Tenya's second kick and suggests that Tenya had forgotten his ability to freeze with precision because he's only been showing off ranged attacks during the festival. After freezing Tenya's body completely, Shoto admits that his opponent's Recipro Burst was too fast to dodge. Midnight declares him the winner and he advances to the final round. After Katsuki advances to the finals as well, Shoto meets his menacing glare.
They meet in the waiting area when Katsuki accidentally barges into the wrong room. Before Katsuki interrupted him, Shoto was mulling over the conflicting memories of his mother's breakdown and Izuku's encouragement. Katsuki tries to intimidate Shoto by slightly blasting the table and warning him to do his best. Mostly unphased, Shoto replies that Izuku told him the same thing, and comments that he was foolish for focusing more on helping him than winning their fight. He asks Katsuki if Izuku was helpful during their childhood, but this only infuriates the former. Katsuki kicks over the table and yells for Shoto to ignore Izuku and his family issues so that he can use his fire during their bout. He angrily exits the room and states he wants to everyone to know he can beat Shoto at full strength.
Their battle begins with Shoto using a more controlled version of the giant ice attack he defeated Hanta with. Katsuki endures the ice blast by tunneling through it using his explosions. Katsuki rushes Shoto and Shoto moves to counterattack, but Katsuki evades using a mid-air explosion and grabs onto Shoto's left side and throws him. Shoto creates and surfs an ice wave to avoid going out of bounds. Katsuki attacks again and Shoto is able to stop him by evading his blast and grabbing onto his forearm. Rather than using the flames in his left arm (the same arm he used to grab Katsuki), he simply tosses him away.
Shoto mulls over his opponent's words, internally apologizing to Katsuki because he is still too unsure about what his left side means to him to use it. Then suddenly, Shoto is once again encouraged by a shouting Izuku, who tells him not to give up and to do his best. Impassioned once again, Shoto ignites his flames and prepares to counter Katsuki's next move. Katsuki readies his special move: Howitzer Impact, but Shoto is haunted by memories of his parents and decides to extinguish the flames and leave himself completely open to Katsuki's powerful explosion. Shoto is knocked out of bounds, and Katsuki is declared the winner.
At the Sports Festival's award ceremony, Shoto is presented with the silver medal by All Might and he inquires to why Shoto refused to use his fire. Shoto replies that although Izuku opened his eyes, he still doubts himself and believes his path to becoming a hero is still clouded. He also mentions that he understands why All Might has such an interest in Izuku. After returning to class, Shoto and the rest of Class 1-A are excused from the next two days of class.
The next day Shoto decides to visit his mother in the psychiatric ward, much to his sister's disapproval. Throughout his life Shoto believed the sight of him would only cause his mother more pain, so he never visited her. Nevertheless, Shoto needed closure from his mother so that he could continue on his path to becoming a hero without anything holding him back. He musters up the courage to approach her, and resolves to talk over everything and free her from the ward's custody.
Once class resumes at U.A., Shoto joins his class in learning about Hero Informatics. Shota reveals the Pro-Hero draft results, with Shoto leading the entire class with 4,123 offers from pros. Midnight joins the class to help the students choose their hero names. Shoto opts to choose his own first name for his code name.
After choosing code names concludes, Shota informs his students that they will choose a hero agency to intern at for a week from a list of their nominations. Shoto notices that his father's workplace is among his choices. When the first day of the internships arrive, Shoto meets with his class at the train station to get his new costume and travel to the office of his choice. Before he departs, Shoto notices that Tenya appears to be unsettled by news of his brother's assault at the hands of Hero Killer: Stain
Shoto reaches Endeavor's agency and gets greeted by his father. He claims Shoto has finally chosen to follow him, but Shoto refutes that, saying that he is following his own path. Endeavor immediately decides to take Shoto out into the field, and they leave for Hosu, Tokyo to track down the Hero Killer.
While in Hosu, Shoto and his father notice an explosion in the distance. Endeavor rushes towards the event, but Shoto receives a message on his cellphone from Izuku with a location on it. He tells his father to go handle the event while he heads to the location, and requests for his father to send him reinforcements.
Shoto arrives at a location just in time to save Tenya from Stain and forces the villain back using a blast of fire. He then scolds Izuku for not supplying any more details in his message since he was almost too late. Shoto tells Izuku that he figured out his message was likely a cry for help and that Pro Heroes are on the way. He uses waves of ice to keep Stain at bay while securing his allies at the same time. Stain evades another stream of fire and Shoto declares he will not allow the hero killer to take anymore lives.
Izuku warns Shoto that Stain's Quirk can paralyze him if he gets some of his blood. Shoto plans to fight at a distance, but Stain catches him off guard and nearly takes his head off with a throwing knife. Shoto narrowly moves his head out of the way and the blade cuts his face open. Stain attacks Shoto from above, but he blocks it using a block of ice. Shoto notices that Stain threw his katana at the same time as a distraction. Shoto's opponent grabs the collar of his costume and almost brings him close enough to lick the blood from his cheek, but Shoto uses his flames in time to repel him.
Stain praises Shoto for his strength and is forced back by combination attacks of both fire and ice. Tenya pleads for Shoto to stop because "Ingenium" must be the one who defeats the hero killer. Shoto replies that his statement is strange because he never saw the scowl of vengeance on Ingenium's face that he sees on Tenya and he knows there is a lot going on behind the scenes in his family as well. He creates a giant wall of ice, but Stain slashes through it and tells Shoto that it is foolish to block his own view when his opponent is farther than him. Stain then stabs Shoto's left with two throwing knives and moves above him.
Just as he is about to stab Shoto from above, Izuku unexpectedly grabs him and tackles him away. Shoto guesses that Stain's Quirk may have a time limit, but Native explains that Izuku was the last to suffer from it, so that cannot be the case. Izuku comes to the conclusion that Stain's Quirk's effectiveness varies depending on blood type, which the hero killer confirms.
Shoto states that he would have liked to carry the injured away but Stain will not give him the opening to do so. He and Izuku decide to hold the villain off until reinforcements arrive. With Shoto already bleeding, Izuku volunteers himself to fight in close quarters while Shoto supports him from a distance. Although reluctant to the risk, Shoto agrees to protect Tenya and Native together with Izuku. He recalls worrying about Tenya ever since Ingenium was attacked because he recognizes someone who is acting on pent-up resentment. Shoto also knows too well how that negativity can cloud someone's judgment.
He remembers visiting his mother and how it cleared up his own perception of her. He told her everything that happened, as she apologized for burning him and forgave Shoto for not visiting her for a long time as she understood his reasons. She also encourages him to move forward in his life without anything holding him back, as that would be her salvation. That is why he decided to intern with Endeavor's agency, not because he has forgiven his father, but because he wishes to learn from the experience of the number two hero. Shoto realizes now that everything could have been simpler for him, but never noticed until Izuku opened his eyes with just a few words.
With the battle's intensity increasing, Stain heightens his strength and overpowers Izuku. He cuts open his leg and licks the blood to paralyze him. Shoto tries to support him, but Tenya again pleads for them to stop. Shoto rejects his plea and tells Tenya to stand up if he wants them to stop. Stain dashes towards Shoto, evading the ice the latter sends at him. Stain slashes through a wall of ice and goes to attack Shoto, who responds by releasing his fire and encourages Tenya to never forget who he wants to become.
As Shoto tries to force Stain back, the villain inches closer to him every time he evades a stream of flames. Shoto uses his ice as well, but Stain is too fast and closes the distance between them. The Hero Killer comments that Shoto is careless because he is too focused on his Quirk and nearly takes him out using the katana. Tenya breaks free from the paralysis in time to save Shoto using his Recipro Burst to break the katana and kick Stain flying back.
Tenya apologizes for getting his friends involved as he states his eyes have been opened, but Stain refutes this and states that Tenya will never reform into a true hero. Shoto tells Tenya not to listen to the villain's words, but Tenya agrees that he is not a true hero. Nevertheless, Tenya believes he cannot give up or else the name of Ingenium will die. Stain attacks again, but Shoto forces him back using his fire. Native urges Shoto to flee, but he refuses and says that Stain will not give him an opening. Although Shoto realizes that Stain's Quirk is not especially effective in a battle against multiple opponents, he notes that Stain has only gotten more tenacious in his attempts to kill his targets.
While Shoto keeps Stain at bay using ranged fire attacks, Tenya asks him if he can regulate temperature. Shoto responds by admitting he is not used to doing so with his left side yet, but Tenya asks him to freeze his legs without blocking the exhausts. Annoyed with Shoto's interference, Stain maneuvers behind him and throws a knife at his head. Tenya moves in front of the blade and it stabs him in the arm and gets pinned down by a second knife. This gives Shoto enough time to do as Tenya asks and cools down the radiators on his leg. This allows Tenya to unveil his new special move: Recipro Extend. Then Tenya and Izuku rush Stain by using their Quirk's to scale the alleyway and strike the Hero Killer simultaneously.
Stain reels back from the student's teamwork and tries to slash Tenya, but he evades and kicks the villain higher into the air. Realizing that this is his chance, Shoto blasts Stain and finally connects with a stream of fire. He secures his allies by using ice to lighten their falls and tells them to get ready to continue fighting. However, Shoto looks up and sees they have actually defeated their opponent.
Shoto restrains the defeated Hero Killer using rope and follows Tenya, and Native carrying Izuku out to the street. He comments that they barely won three on one with Stain making several mistakes and that it is likely Stain became flustered and forgot Izuku's recovery time, making him unable to compensate for their last joint assault. They are met by several Pro-Heroes who offer to call an ambulance and the police. Tenya cries and takes a moment to ask for his friend's forgiveness and Shoto says that Tenya is the class president and needs to pull himself together.
Then suddenly the last Nomu swoops down from the sky and snares Izuku. Before it gets to far away, Stain recovers and uses his Quirk to stop it. Then he saves Izuku by grabbing him and stabbing Nomu's brain. In spite of being heavily injured, Stain states that the "fake" pro heroes and the pathetic criminals in society must be purged to create a more just society. Shoto and everyone are taken back by his actions. Stain challenges all the heroes to try and stop him. The bandages over his face fall off and he releases a malicious aura that paralyzes everyone with fear, including Shoto. The Hero Killer prepares to attack, but his perforated lungs cause him to lose consciousness.
Shoto, Izuku, and Tenya are taken to Hosu General Hospital and spend most of the night without sleep. The next morning, the trio dicuss their encounter with the Hero Killer and Shoto claims that he likely spared their lives. Their conversation is interrupted when the Chief of Hosu City Police, Kenji Tsuragamae arrives. He informs them that Stain is undergoing treatment for his injuries and because they acted on their own without permission, they must be punished.
Shoto is outraged at the idea that the Police expected he and his peers to follow the law and allow people to die as a result, arguing that it is the job of a Hero to save others. He nearly lashes out, but Gran Torino stops him and pleads for him to hear Kenji out. Since there were not enough witnesses to report the incident regarding Stain the incident will remain undisclosed. However, as a result, Izuku, Shoto, and Tenya will not get any recognition for their valiant efforts. After Kenji shows his gratitude Shoto says that the chief should have lead the conversation with that, and the trio thank him for pardoning them.
The following day, when Izuku returns to their room, Shoto informs Izuku that Tenya got his medical results back. Tenya reveals that his hand was badly damaged in the battle and he will not heal it so it serves as a reminder of his un-heroic deeds. Izuku promises to do the same and they make a pact to become stronger.
Shoto apologizes for being cursed, as it seems whenever he is involved in a skirmish, that his friends' hands get messed up. Izuku and Tenya are surprised that Shoto can crack a joke, but he claims to be completely serious, calling himself a "hand crusher" and leading the young Heroes to laugh together.
When the week concludes and the internships end, Shoto returns to U.A. High. His peers question Izuku, Tenya, and himself about the incident in Hosu. Sworn to silence by the Police Chief, Shoto covers up the truth and says Endeavor saved them all from Stain. In their next Basic Hero Training class, the class participates in rescue races.
During the first race, Shoto notices Izuku's new moves are very similar to the way Katsuki flies around using his explosions.
One week before final exams, Aizawa reminds Class 1-A to study for their written and practical components before ending class. Denki and Mina admit they havent studied at all because of the events that have taken place throughout the term. Having placed fifth on the midterms, Shoto comments that if they paid attention in class they wouldn't have a problem.
During lunch, Shoto sits with Izuku, Tenya, Shoto, Ochaco, Tsuyu Asui, and Toru. He listens as they discuss what they believe the practical test will contain. They learn from Itsuka Kendo that the test may consist of fighting against robotic villains. Back in class, Denki and Mina are delighted by this, but Katsuki is annoyed by their behavior. He yells at them, and then openly claims he will receive a better grade then both Shoto and Izuku before storming out.
A week passes and Class 1-A finishes the written section of the finals. They change into their hero costumes and join their teaches at the practical exam area. There, Principal Nezu announces the practical portion will involve pairs of students facing off against one teacher. Shoto is paired with Momo Yaoyorozu. Prior to that day, the teachers discussed the pairings. Aizawa states he paired Shoto with Momo because they both rely too heavily on their Quirks, so he will erase them.
After the first three matches conclude, Shoto and Momo meet in a replica city. He asks if Momo is nervous about facing their homeroom teacher and says he has a plan. The match begins and they run through the city. Shoto instructs Momo to keep making small objects so they will notice when Aizawa is nearby, and once he is Shoto plans to distract him while Momo runs for the exit. He instructs Momo not to get separated from him until then. Momo reluctantly agrees and they continue on. She makes Russian matryoshka dolls, prompting Shoto to tell her if she notices anything strange. She commends Shoto for coming up with a quick plan, but he replies it is nothing special.
Momo suddenly stops and tells Shoto that although they both started as students who got into U.A. through recommendations; she has not done anything to stand out like he has. Shoto interrupts, noticing that she has stopped producing the dolls. They realize that Aizawa is close, but he surprises them when he reveals himself hanging from a power line. Shoto tries to freeze him, but Aizawa has erased his Quirk. He kicks at Aizawa and tells Momo to run, but is quickly restrained by his teacher. Disappointed in Shoto's plan, Aizawa says he was planning to catch Shoto anyway and hangs him from the power lines. Shoto replies that he could burn or freeze his restraints at any time, but Aizawa throws caltrops below him. Aizawa also mentions that Shoto should have talked over his plan more with Momo.
Aizawa leaves and Shoto ponders his words, recalling that Momo wanted to say something earlier about the plan. Momo returns shortly after and apologizes, but Shoto warns her Aizawa is in pursuit. Momo becomes nervous and indecisive, so Shoto decides to ask her if she has an idea. He apologizes for not talking it over more. Momo claims her plan cannot work if Shoto's failed, but Shoto claims that Momo is more fit for planning. Shoto reveals that he believes in her leadership so strongly that he voted for her to be class president. Shoto's words help reinvigorate Momo's confidence. She throws the dolls at Aizawa, revealing the flash grenades inside. The explosion of light gives Momo enough time to free Shoto, and she claims to have a special plan to defeat their homeroom teacher.
Shoto asks Momo what her idea is but Aizawa interrupts and attacks them. Shoto tries to counter using his fire, only to realize his Quirk has been erased again. Momo instructs them to run and find a place to hide outside Aizawa's field of vision. As they are running, they discuss how Aizawa's Quirk has weakened since the attack on the U.S.J. and Momo states it is a bad idea to assume they cannot use their Quirks. Aizawa closes in on them and Momo says there will be a moment when their Quirks will come back. When that moment comes and Aizawa blinks, Shoto attacks using his Giant Ice Wall technique.
Now protected by the giant ridge of ice, Shoto asks what Momo's plan is. He awkwardly turns around to notice her opening her shirt to create a weapon similar to Aizawa's scarf. She replies it is slightly modified to her own version and goes on to share her plan with Shoto. He does not object and they run from behind the ice wearing dark cloaks. Aizawa moves quickly and restrains them with his capture weapon, but Momo reveals their upper bodies were only mannequins. She creates a catapult and uses the opening to send the weapon at him. Shoto uses his flames to heat the weapon made from shape memory alloy, causing it to tighten and bind Aizawa.
They handcuff their teacher soon after and Shoto questions if the plan went too smoothly. Momo admits she initially missed the catapult lever, giving Aizawa an opening to stop them. When she asks why Aizawa hesitated, he claims to have been cautious of Shoto because he was still cloaked at the time. Shoto thanks Momo for her plan and she starts to get teary-eyed. He asks if she feels sick and offers advice, but she says it is nothing.
After all practical exams conclude, Class 1-A returns to class the next day. Shoto learns he passed both the written and practical ends of the finals, and will attend training camp over the summer. His classmates opt to go to the mall to prepare, but Shoto decides to visit his mother instead.
A day prior to summer break, Izuku invites Shoto and the other boys from Class 1-A to the pool for endurance training. They hold competitive swimming races and Shoto wins his leg by freezing the pool instead of actually swimming. Just before Shoto, Izuku, and Katsuki compete in the final race, Shota arrives and tells them they're out of time to use the pool and kicks them out. Afterward, Shoto, Tenya, and Izuku recall their battle with Stain and how far they've come as budding heroes in the making. 
Summer break begins and Class 1-A rides a bus to a forest reserve belonging to the hero team: The Wild, Wild Pussycats. Pixie-Bob and Mandalay introduce themselves and challenge the students to reach base camp past the forest in three hours. When most of Shoto's peers refuse, he and his class are forcibly thrown into Beast's Forest by Pixie-Bob's quirk.
A monster created from dirt clods immediately attacks Minoru. Shoto works together with Izuku, Katsuki, and Tenya to defeat it. Class 1-A works together to fight their way through Beast's Forest. They encounter several different dirt monsters. Shoto and Katsuki take one out together, much to Katsuki's displeasure. Class 1-A doesn't arrive at basecamp for several more hours. Well over their time limit, Class 1-A arrives at the base camp exhausted and battered. Mandalay reveals the time limit was the expectancy for actual heroes, not the students. Mandalay's nephew Kota, punches Izuku in his groin. Katsuki says the boy is precious, and Shoto compares the two to each other. The Pussycats serve the students dinner and the boys bathe in the hot springs afterward.
Training begins the next day. Shoto trains by sitting in a pot of bathwater and changes its temperature by constantly switching between fire and ice. Later that day, the students are tasked with cooking curry for themselves. Shoto uses his fire to light several of the stoves, including one for Ochaco and Mina. He smiles because he's able to use his fire without restraint, and can use it to help others. After another day of training, Shoto asks Izuku why he inquired to Shota about All Might. He gives Izuku advice on handling a delicate situation with Kota. Shoto tells him that actions inspire others, not just words.
That night, Shoto and Katsuki are paired together for the test of courage. Class 1-A students roam the forest while Class 1-B students try to scare them. The duo is slightly shaken by a Yui Kodai and Ragdoll. The League of Villain's Vanguard Action Squad attacks the camp. Shoto, carrying an injured Kosei Tsuburaba, runs through the forest with Katsuki. While going back to the facility, Shoto and Katsuki encounter Moonfish admiring a severed arm on the ground. The villain turns his attention to Katsuki and Shoto.
Katsuki rushes Moonfish, prompting the villain to attack with his quirk. Shoto blocks the tooth blades with an ice wall and warns Katsuki not to rush into a fight. The blades pierce the ice and nearly hit Katsuki, only to be intercepted again by Shoto's ice. Moonfish evades the ice attack and moves fluidly through the treetops. Frustrated, Shoto comments that Moonfish likely has a lot of experience fighting and they need to be careful. Katsuki wants to counterattack but Shoto sternly warns him not to start any fires. Shoto analyses their situation and realizes that retreat isn't possible because of the poison gas surrounding them. He concludes that the villains are trying to drive the students into a corner. 
Shoto is unable to fight properly as he's carrying Kosei, and he can't use his fire without risking the lives of those in the forest. He does his best to continue defending against Moonfish's onslaught. Katsuki becomes irritated that he's unable to fight back and expresses his desire to attack Moonfish with a big explosion. Shoto advises against it and Katsuki replies that Shoto needs to freeze the trees should they get set ablaze. Shoto still refutes this and explains the explosion might impair his vision, making him unable to see the fire.
Suddenly Shoto notices Mezo carrying Izuku towards them while running from a gigantic, berserk Dark Shadow. Mezo pleads with Shoto and Katsuki and asks them to create light with their quirks. The rampaging Dark Shadow knocks Moonfish out of the air and crushes him. Shoto prepares to use his fire to weaken Fumikage's quirk, but Katsuki tells him to wait until Dark Shadow finishes Moonfish off. As soon as Dark Shadow defeats Moonfish, Shoto and Katsuki use their quirks to create light and free Fumikage from Dark Shadow's control.
Shoto admits he's surprised Fumikage's Dark Shadow was able to defeat Moonfish so easily after barely being able to defend against the villain himself. Shoto, Izuku, Mezo, and Fumikage decide they need to protect Katsuki at all costs. They form the Bakugo Escort Team and decide to take a shortcut through the forest to get him back to the facility. Katsuki claims he doesn't need protection, but Shoto tells him they will surround him for the time being.
While on their way to base camp, the group happens upon Ochaco and Tsuyu fighting with Himiko Toga. Himiko retreats and Izuku asks them to join their group. The girls question why Katsuki is not with them, forcing the group to realize that Katsuki is missing. Mr. Compress appears and reveals that he took him with his "magic".
Izuku demands the villain return Katsuki and Shoto agrees while attacking with a wave of ice. Mr. Compress easily evades by jumping through the treetops and says that the League of Villains wish to show him more options than the fanatical world of heroism he's drowning in. Mezo points out that Fumikage is missing as well and Shoto mulls over the fact that the villain was able to snatch two of his strongest classmates without a sound. Angry, Shoto replies to Mr. Compress' monologuing by telling him not to underestimate the students. Mr. Compress explains he took Fumikage because of how easily and violently he defeated Moonfish.
Shoto hands Kosei off to Ochaco and attempts to freeze Mr. Compress with a massive ice wave. He's surprised when Mr. Compress evades him again and says that the villains are going to take their friends. Izuku says they can't and Shoto agrees to chase after Mr. Compress in order to stop them.
Shoto and company chase after the masked villain, but he's too quick for them to catch on foot. Izuku devises a plan to use Ochaco and Tsuyu's quirk to propel the boys through the air. Ochaco nullifies their gravity, Tsuyu throws them and Mezo guides them through the air until they're able to tackle Mr. Compress into the ground. They land directly in front of Dabi, Himiko and Twice.
Dabi launches his flames towards the boys, allowing Mr. Compress to escape. Shoto manages to dodge Dabi's flames, but Izuku and Mezo do not. In an instant, Twice appears behind Shoto and attacks him, but Shoto blocks the attack with his ice. Shoto continues to hold back Twice until Mezo reveals that he took the marbles from Mr. Compress. Shoto, Mezo, and Izuku flee, but they get cut off by the sudden arrival of Kurogiri.
Mr. Compress reveals he compressed Shoto's ice to fool the students, and reveals he has the real marbles trapped in his mouth. Yuga shoots his laser from behind a bush and blasts Mr. Compress' face. He drops the marbles out of his mouth. Mezo is able to save Fumikage, but Dabi grabs the second marble before Shoto can get to it. Shoto watches in horror as Katsuki reverts to his normal form and is forced into Kurogiri's warp gate.
The following days, Shoto visits Izuku and his classmates in the hospital. He runs into Eijiro and they agree they can't stay home while their friends remain injured. They both overhear Momo talking to All Might about a tracking device she placed on a Nomu. Shoto along with many students from Class 1-A visit Izuku on the day he wakes up from his injuries. 
Two days after the incident, Shoto and the rest of his classmates visit Izuku in the hospital. Shoto and Eijiro state their plan to rescue Katsuki after overhearing Momo talking about a device that can locate a transmitter she placed on one of the villains. However, most of Class 1-A are against the idea. Shoto leaves after the doctor needs to checkup on Izuku.
Later that night, Shoto along Eijiro wait for Izuku and Momo. They arrive, but before Momo can speak, Tenya appears, angry that they are about to repeat the same mistake he made at Hosu. Shoto tells Tenya that they will not engage the villains in combat, and Eijiro explains that they are planning a covert mission. Momo states that she came along to accompany them all in order to prevent them from engaging in combat. Tenya decides to go with them.Shoto along with Izuku, Momo, Tenya and Eijiro board a train to travel to a place called Kamino Ward, located in Yokohama City in the Kanagawa Prefecture. At the location, the group puts on disguises to prevent the League of Villains from recognizing them. They exit the clothing shop and witness a video clip of U.A.'s public apology.
Shoto along with Eijiro, Izuku, Momo and Tenya continue towards the place that Momo's tracking device is detecting. After waiting for a while near the place, Momo, Tenya, Shoto, Eijiro, and Izuku prepare to infiltrate the supposed League of Villains' hideout.
Shoto along with the group go to the back of the hideout and see a window. Shoto and Tenya have Izuku and Eijiro stand on their shoulders to see what is inside using the night-vision goggles Eijiro brought along. Suddenly, Mount Lady destroys the front of the warehouse which shocks Shoto.
Seeing that the Pro Heroes are at the warehouse, Shoto and the group assume that All Might is with Katsuki as they are speaking. Shoto and the group decide to head home. Suddenly, the entire warehouse is completely destroyed by a mysterious man along with the surrounding area being significantly damaged. The man's aura above them utterly terrifies Izuku, Eijiro, and Shoto.
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 not any openings to rescue Katsuki due to Sensei’s presence and Katsuki being outnumbered by the Vanguard Action Squad. Suddenly, Izuku comes up with an idea and explains the plan to Shoto and the rest of the group.
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.
Seeing that Izuku, Eijiro and Tenya have succeeded in rescuing Katsuki, Shoto and Momo begin escaping from the battlefield.
Shoto and Momo successfully escape. Shoto phones Izuku and finds out that him and his group are at the train station.
Shoto and Momo meet up with Izuku's group. They take Katsuki to a Police Station for his safety. Afterwards, Shoto parts ways and goes home. Shoto arrives at the Todoroki Abode where his sister greets him and states that their father is in the training hall. Shoto walks by the training room and assumes that his father will take the position of Number One Hero now that All Might can no longer fight. Shoto sees the training hall, only to find that the room is nearly in shambles due to Endeavor's rage; Endeavor refuses to accept the position of Number One Hero.
At Ochaco's urgings, Shoto along with Izuku, Tenya, Momo, and Eijiro all meet outside the dorm where they find her with Tsuyu. Tsuyu apologizes for harshly doubting their plan to save Katsuki, as they apologize for worrying her and they manage mend their friendship.
Along the rest of his class, Shoto takes the Provisional Hero License Exam in hopes of gaining a Provisional Hero License, a document that would allow him to use his quirk on heroic activities without repercussion. He is seen standing by Izuku as Aizawa explains to him how Inasa Yoarashi had been one of the recommended students to take the exams in the same years as Class 1-A's students, and having in fact achieved the highest grades out of any recommended student. This causes Izuku to wonder whether Inasa could be even stronger than Todoroki himself, another recommended student of that yet.
Once the first phase of the exams starts, Shoto quickly runs off by his own rather than staying with the rest of his classmates, claiming he would be able to use his power better alone than in a group with them. He is later seen using both his fire and ice against a group of fellow examinees. Having managed to eliminate them and guaranteeing his position on the second phase of the exams, he silently muses on how he still hasn't gotten used to using both his right and left sides simultaneously, and therefore feels sluggish while doing so.
Later on, Shoto and Katsuki retake the Hero License exam with Inasa and Camie Utsushimi. While there, they have to fight against the new generation of kids who have strong quirks. Shoto ends up passing his exam alongside the others.
At U.A. High School, Class 1-A along with Shoto choose to make a band and dance performance for the U.A. culture festival.
Back in Class 1-A's Heights Alliance, Tenya Iida is busy helping plan Class 1-A band and dance performance. Katsuki also expresses his discontent with Class 1-A presenting the band and dance performance as a stress reliever, believing people who sicken him do not deserve his courtesy, and states that all they are doing is indulging the other students. Tenya and Momo Yaoyorozu take Katsuki's views into consideration as Shoto Todoroki points out that Katsuki should not speak ill of them if he has not even partaken in the conversation. Katsuki tells them that they do not fight villains because they enjoy it and likewise they should not consider people's feelings for a band and dance performance; if they are going to do a band and dance performance, they should do it for the sake of it and not to please or help people. Katsuki announces that he will blow everyone away in U.A. with his sound. Shoto and some of Class 1-A are surprised with Katsuki's willingness to participate.