Tetsutetsu is a young man with long gray hair that never appears to change shape, no eyebrows and thick pale eyelashes that encompass his eyes. Like Eijiro Kirishima, he also has razor-sharp teeth.
Tetsutetsu's hero costume consists of a dark green sleeveless jumpsuit with metal boots and metal straps over his shoulders, the straps connect at a red circle on his chest. He also has metal bands around either of his biceps and a mask.
Tetsutetsu is defined by his very hot-headed and outspoken personality. He is confident, stubborn and very straightforward in both his motivations and his actions. He tends to be very vocal about his intentions and has a one-track mind. Tetsutetsu often looks for the simplest solution to problems in order to go about them in the most direct manner. Even when fighting, Tetsutetsu's direct personality shows through his tenacious and upfront fighting style.
Determined to prove himself, Tetsutetsu desires to be put on the same skill level as the students in Class 1-A. When Tetsutetsu first met Class 1-A, he was very loud and abrupt in his introduction because he felt they considered themselves superior to Class 1-B. He especially detested Katsuki for his arrogance and resolved to win the Sports Festival as a result.
Despite his stubbornness, Tetsutetsu eventually befriended Eijiro of Class 1-A and even cheered for him during the festival. Even so, Tetsutetsu continued to try and prove himself as a student on par with Class 1-A.
Following the end of the first term, the Class 1-B students were considered second-rate by everyone including their homeroom teacher. Tetsutetsu was brought to tears while apologizing for disappointing his teacher. When villains attacked both classes, Tetsutetsu fought back as an opportunity to expose himself to danger and grow from it. Much like Class 1-A did during the attack on the U.S.J.
Tetsutetsu appears to care deeply about his peers. He didn't attack the villains before ensuring Ibara Shiozaki's safety and didn't hesitate to throw himself in front of a bullet for Itsuka Kendo.
Steel (スティール Sutīru?): Tetsutetsu's Quirk allows him to turn his body into steel, which gives him a great defensive ability. He can also use it offensively to increase the strength of his unarmed attacks. Upon losing an arm wrestling match he mentions that he should have had more iron that morning, possibly implying that his quirk strength is fueled and affected by his diet containing iron.
Battles & Events
- Eijiro Kirishima vs. Tetsutetsu Tetsutetsu: Draw, later lost on the arm wrestling contest.
- His name is composed of the kanji for "iron" (鉄?), "clear" (哲?), "pierce" (徹?), and an archaic kanji for "iron" (鐵?). Aside from being a clear reference to his quirk, his name may be a joke on how similar he is to Eijiro Kirishima; his name sounds redundant, with each kanji being pronounced like the word for "iron". Additionally he and his Quirk were formally introduced in quick succession and in an identical situation to Eijiro.
- Tetsutetsu ranked 8th during the Entrance Exam with 49 Villain Points and 10 Rescue Points.
- According to Tetsutetsu's profile in Volume 4:
- He likes fighting games.
- His favorite food is spinach.
- Kohei likes his design and wants to draw more of him.
- Tetsutetsu shares several similarities with Eijiro Kirishima.
- They share the same birthday (October 16).
- They both chose Fourth Kind's office for workplace experience.
- They share the same stats.
- Their Quirks, Steel and Hardening, are functionally similar and described likewise.
- Both have sharp teeth.
- In the anime, their Sports Festival entry poses were the exact same.
- Tetsutetsu ranked in the Top 16 of the U.A. Sports Festival First-Year Stage.
- Tetsutetsu also shares similarities to Gajeel Redfox from Fairy Tail, as both characters are voiced by David Wald in the English Dub, as well as using steel for their power.
- It's worth noting that Gajeel's Japanese voice, Wataru Hatano, voices fellow classmate, a student in 1-C, Hitoshi Shinso.
- Tetsutetsu and his Quirk might be references to the Japanese cyberpunk horror film Tetsuo: The Iron Man.
- His Quirk, Steel, is a reference to the DC Comics hero Citizen Steel, whose skin and muscle tissue are transmuted into organic steel. It might, however, be a reference to the Marvel Comics hero Colossus, who can transform his skin to organic metal at will.
- Tetsutetsu's English voice actor, David Wald, also voices Snipe.
- (To Itsuka Kendo) "I'm in Class 1-B of the Hero Course! If I don't stand up here, what's the point?! I'm gonna find these jerks and beat the snot out of them!"