Ha ha! How'd you like that? It's an invisible wall!
Kosei Tsuburaba

Kosei Tsuburaba ( (つぶら) () (こう) (せい) Tsuburaba Kōsei?) also known as Tsuburaba (ツブラバ Tsuburaba?)[1], 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, along with his large pupils.

His hero costume consists of a simple light blue jacket, with pale pants, a black shirt underneath, and he wears large brown boots with cylindrical shapes on the soles.


Kosei is a very enthusiastic and competitive individual who holds 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. Similar to Neito Monoma, Kosei has no problem settling for less rather than aiming for the top.[2]

He seems to have a subtle yet rather lecherous side, which is demonstrated in how he was mostly thinking about how Tsuyu Asui's tongue was wrapped around him when he was captured.



Solid Air ( (くう) () (ぎょう) () Kūkigyōko?): Kosei's Quirk allows him to solidify any air he breathes out, allowing him to create invisible walls and/or platforms. The solidified air continues to stay afloat in midair, even if someone is standing on it. The size of the wall or platform depends on his lung capacity.

Initially, these walls and platforms were not very strong, as Katsuki was able to break an air wall as if it were made out of glass using only his bare fist, uninjured. Later on, he improved his Quirk and his air walls were strong enough that it required hitting them with metal pipes to break them.

The solidified air is also soundproof, making it effective against Quirks that rely on sound, such as Anivoice or Brainwashing.

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

Chapter Appearances

U.A. Sports Festival Arc
22. That's the Idea, Ochaco Absent
23. Roaring Sports Festival Absent
24. Mad Dash and Knockdown Absent
25. In Their Own Quirky Ways Absent
26. Chase Down the Leader Debut
27. Earth-Shatteringly Fateful Negotiations Appears
28. Strats, Strats, Strats Appears
29. Unaware Appears
30. Cavalry-Match Finale Appears
31. The Boy Born with Everything Absent
32. Smile, Prince of Nonsense Land! Absent
33. Shinso's Situation Absent
34. Victory or Defeat Absent
35. Battle On, Challengers! Absent
36. Bakugo vs. Uraraka Appears
37. Midoriya and Endeavor Absent
38. Todoroki vs. Midoriya Absent
39. Shoto Todoroki: Origin Absent
40. Emancipation Absent
41. Fight On, Ida Absent
42. Final-Match Time Absent
43. Todoroki vs. Bakugo Absent
44. Relaxing Day Off Absent
Forest Training Camp Arc
70. Wild, Wild Pussycats Appears
71. Kota Absent
72. Day Two Absent
73. Good Evening Absent
74. Smoke Signal Absent
75. Stake Your Life, Hero! Appears
76. My Hero Absent
77. It's Okay Appears
78. Whirling Chaos Appears
79. Drive It Home, Iron Fist!!! Appears
80. Establishing the Bakugo Bodyguard Brigade Appears
81. Roaring Upheaval Appears
82. What a Twist! Absent
83. Loss Appears
Provisional Hero License Exam Arc
98. Moving into Dorms Absent
99. Goodbye Two-Digit Chapters, Hello Three Digits Absent
100. Creating Ultimate Moves Absent
101. The Girl Called Mei Hatsume Absent
102. On Cloud Nine Absent
103. The Test Absent
104. White-Hot Battle! To Each Their Own Strengths! Absent
105. Shiketsu High Lurking Absent
106. Class 1-A Absent
107. Denki Kaminari's Thoughts Absent
108. RUSH! Absent
109. Rescue Exercise Absent
110. Rescue Exercise Continued Absent
111. Smoldering Start Absent
112. What's the Big Idea? Absent
113. Test's Aftermath Absent
114. Result's Aftermath Absent
115. Unleashed Absent
116. Meeting in Tartarus Absent
117. A Talk About Your Quirk Absent
118. Meaningless Battle Absent
119. Deku vs. Kacchan, Part 2 Absent
120. The Three Absent
121. Second Semester Opening Ceremony Appears
Joint Training Arc
194. Cold Skies Over U.A. High! Absent
195. Clash! Class A vs. Class B! Appears
196. Make It Happen, Shinso!! Appears
197. Quaotic Quirkstravaganza Appears
198. Known Where You Stand When It Counts!! Appears
199. Operation New Improv Moves! Absent
200. Clever Commander! Absent
201. Foresight Absent
202. Match 3 Absent
203. Flexible! Juzo Honenuki! Absent
204. Tuning Up Absent
205. Detour Absent
206. Match 3 Conclusion Absent
207. Early Bird! Absent
208. Match 4 Conclusion Absent
209. Match 5 Start Fantasy
210. The One For All Dream Absent
211. That Which Is Inherited Absent
212. That Which Is Inherited, Part 2 Absent
213. Realm of Souls Absent
214. Our Brawl Appears
215. Final Face-Off! Midoriya vs. Shinso! Absent
216. Class A vs. Class B: Conclusion Appears
217. The New Power and All For One Appears
Endeavor Agency Arc
241. Do That Interview! Absent
242. Have a Merry Christmas! Absent
243. Off to Endeavor's Agency! Absent
244. Recommended Reading Absent
245. Rise to Action Absent
246. Message Appears
247. Status Report! Absent
248. One Thing at a Time Absent
249. The Hellish Todoroki Family Absent
250. Ending Absent
251. Just One Week Absent
252. The Unforgiven Absent


  • 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 is the only character in the main series so far to receive more than one volume character profile.
  • Kosei likes ball games.[3]
  • Kosei likes any kind of live-action television that features superheroes and makes considerable use of special effects.[1]
  • Kosei's first English voice actor, Aaron Dismuke, also voices Tamaki Amajiki. His second English voice actor, Nazeeh Tarsha, also voices Electoplant and Daigo.



  1. 1.0 1.1 My Hero Academia Manga: Vol. 23, Omake
  2. My Hero Academia Anime: Episode 18.
  3. My Hero Academia Manga: Vol. 10, Omake

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