Kosei Tsuburaba ( (つぶら) () (こう) (せい) Tsuburaba Kōsei?), is a student in Class 1-B at U.A. High School, training to become a Pro Hero.


Kosei is a young man with short brown hair, spiked up at odd angles on his head. His eyes are oval-shaped, and as are his large pupils.

His hero costume consists of a simple, light-colored jacket, with matching pants, a dark shirt underneath, and he wears large boots with cylindrical shapes on the soles.


Kosei is a very enthusiastic and competitive individual who tries to hold himself to a high standard as he makes an effort to avoid descending to the level of his rivals.

However, Kosei was not above taunting Katsuki Bakugo himself after stopping the Class 1-A student with his Quirk. Similarly to Neito Monoma, Kosei has no problem settling for less rather than aiming for the top.[1]

Kosei's debauched tendencies

He seems to have a subtle yet lecherous side of him, as shown when he got captured and he was mostly thinking about how Tsuyu Asui's tongue was wrapped around him.



Solid Air ( (くう) () (ぎょう) () Kūkigyōko?): Kosei's Quirk allows him to solidify any air he breathes out.

He can use this ability to form walls or platforms. The size of the wall or platform depends on his lung capacity. It seems that these walls and platforms are not very strong, as Katsuki is able to break a wall as if it were made out of glass using only his bare fist, and his fist did not look injured in the slightest, this weakness is overcome after much training.

The solidified air is invisible.

Super Moves

  • Air Prison (エアプリズン Ea Purizun?): Kosei refined his Quirk since the Forest Training Camp Arc, and is able to send out squares of air, and shape them into a box to imprison his opponent. The fact that Koji Koda was imprisoned there for a while and Jurota Shishida had problems containing Koji's strength shows that these air prisons are much more durable than solid air he has shown previously. He displays this ability in the first round of the Class 1-A vs Class 1-B training event.


2/6 D
3/6 C
5/6 A+
4/6 B
Got Your Back
5/6 A+
Kosei's stats, according to the Ultra Analysis Book

Battles & Events

Battles & Events


  • Kosei's surname contains the kanji for "yen, circle" ( tsubura?) and "place" ( ba?), and his first name contains "hardness" ( ?) and "formation, to become" ( sei?).
    • Kosei's first name is a homonym of the word for "Quirk" (個性 kosei?) in Japanese.
  • Kosei is the only character in the whole series so far to receive more than one volume character profile.
    • Kosei's first character profile reveals he likes ball games.
  • According to Volume 21, Kosei appears to like any kind of live-action television that features superheroes and makes considerable use of special effects.



  1. My Hero Academia Anime: Episode 18.

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