There are so many capable men... and all they can think to do is rob a convenience store? Kinda weird... you'd think a group this big might just, y'know... have bigger goals than that... You're all sick. And you need a cure.
Kai Chisaki to Team Reservoir Dogs in "Unleashed"

This article is about the character. For this character's Quirk, see Overhaul.

Kai Chisaki ( () (さき) (かい) Chisaki Kai?),[2] also known by the villain name Overhaul (オーバーホール Ōbāhōru?), was the Yakuza Captain of the Shie Hassaikai.[3] He serves as the primary antagonist of the Shie Hassaikai Arc and is currently imprisoned in Tartarus.


Kai is a pale man of narrow build with short, shaggy auburn hair, parted to the left. His eyes are thin, their irises small and gold, with rather long lower eyelashes and small eyebrows. He also possesses a small scar on the left side of his forehead that he acquired as a result of his fight with the League of Villains. He has three piercings in his left ear. He usually has his mouth covered by a plague doctor mask, following his battle with Izuku Midoriya, however, his mask is removed and his mouth is consequently uncovered, and he also lost both of his arms to Mr. Compress and Tomura Shigaraki.

Kai wears a black dress shirt with matching dress pants, a pale gray tie around his neck and a belt with a long, thin buckle around his waist, with three beaded lobe piercings in his left ear. Over this, he wears a dark olive-green bomber jacket, its collar lined with thick purple fur, and white lace-up sneakers, their soles tan-colored, with no socks on his feet. His most noticeable features are the white surgical gloves he wears on his hands and the magenta plague mask he wears over his mouth, which is tipped and embroidered with gold.



After fusing with Shin Nemoto, Overhaul gets an additional two arms deformed with spiked claws and black parts of Shin's cape. His hair gets spikier, and his mask rips apart, seeming to be fused onto his face, which is also covered in black fabric. Shin is presumably conscious in the fused form as his mouth is used through Overhaul's right hand and his Quirk is in use.[4]

After fusing with Rikiya Katsukame, Overhaul's lower body is fused into a monstrous stone structure, protruding multiple appendages each equipped with clawed hands. Overhaul's upper body is the same but lies within the mouth of the structure, and his upper jaw has Rikiya's mask.[5]


Overhaul using Eri to destroy Quirks

A symbolic representation of Overhaul's twisted plans.

Overhaul is a mysophobic, antisocial sociopath obsessed with returning the world to the way it was before the Quirk phenomenon. Due to a combination of an old theory claiming Quirks derived from rats and his own mysophobia, Overhaul believes that Quirks are actually a plague on humanity, having infected people with "syndromes" of heroism and villainy. He looks down upon those that use their abilities for either purpose, referring to acts of heroic sacrifice or petty crime as "sicknesses".[6][7] Overhaul is extremely determined to his ambition of eradicating Quirks, not only due to his own personal phobias, but also because such a thing would allow the yakuza to reclaim the power they once held over society. Overhaul has no moral compass and an enormous ego, viewing himself as the only person in the world that's enlightened to the "true nature" of Quirks and deserving of the spot as ruler of the underworld after the fall of All For One. In spite of this, Overhaul's values are noted to be paradoxical, particularly his overreliance on a Quirk that he happened to name himself after.[8]

As the leader of the Shie Hassaikai, Overhaul is usually levelheaded, thinks strategically, and, according to a conversation with Twice, seems to be nice at first. Whether he is acting or behaving genuinely, Overhaul does possess polite mannerisms and can come off as very calm and classy even to people he considers potentially troublesome, this being evident in his first meeting with Mirio Togata and Izuku Midoriya. If aggravated, however, he may end up displaying a powerful and visible killing intent, more fitting of his true character.

I have no Children

Kai's germophobia causing him to break out in hives.

Overhaul is very germophobic and hates anything he perceives as unsanitary, frequently remarking about the unclean appearances of certain people and locations. He refuses to be touched by others, or even breathe in the same air as theirs, which is one of the reasons he wears an air-filtering plague doctor mask and forces his subordinates to do the same while around him. If blood, dirt or some other unclean substance comes in contact with Overhaul's person, he will start developing hives and lose his usual composure, becoming increasingly unhinged as a result. In drastic circumstances though, Overhaul will let go of his aversions in order to crush an enemy that's standing on his way, either due to pragmatism or out of sheer hatred.

Overhaul kills Eri's minder

Overhaul after disposing of one of his subordinates.

Overhaul doesn’t value humans, viewing people as pawns for their utilitarian value and being willing to experiment on them to accomplish his objectives. He carries this sentiment even towards the other members of the organization he has dedicating himself to since childhood, treating them as expendable sacrifices for his well-being and having no qualms in killing them off for the smallest mistakes. The masks worn by his closest subordinates also serve as a reminder of this mindset; he doesn't view them as worthy of sharing the same air as his. Even Eri, the centerpiece of his operations, is not spared from this brutal way of thinking as he frequently shames and abuses her through threats and guilt trips, seemingly as a method to force subservience on her mind.

Kai Chisaki remembers his debt

Kai’s fierce determination to revive the Yakuza and repay his debt.

The only person Kai has ever shown concern for is the former boss of the Shie Hassaikai, who rescued him from the streets as a youngster and raised him as a yakuza. Kai, to this day, still feels deeply indebted to his boss for taking him in, being adamant in returning said debt by returning the yakuza to their glory days somehow.

As a young yakuza, Kai was extremely ruthless and would kill anyone who didn't show the Shie Hassaikai the proper respect, constantly getting into fights with rival gangs. Kai's boss, who was growing aware of the violent, immoral path his underling was following to uphold the name of the Shie Hassaikai, attempted to sway him towards a more honorable course, but to no avail; Kai became more and more convinced that illegal, questionable dealings were the only way the yakuza could ever restore their former honor. This would lead the misanthropic Kai to develop an interest in the boss's granddaughter, because he considered her rewinding abilities a golden opportunity for the Shie Hassaikai, believing that he could produce a Quirk-Destroying Drug out of her cells that would give the yakuza enough power to take control of the black market.

Kai, despite his loyalty and indebtedness to his superior, could not accept his boss's disagreement over the idea, attacking and leaving him in a comatose state to work on his plan unimpeded. Kai took over the Shie Hassaikai under the twisted assumption that everything he was doing was for the sake of his boss and the organization.

In the end, Overhaul's failure to recognize others and his own obstinate nature result in his downfall. Despite his strong-willed attitude, he is capable of expressing true fear and shock, especially post-defeat, after the League of Villains took away his product and ability to use his Quirk.[8]


Overall Abilities: Prior to his dismemberment Overhaul was an incredibly powerful villain that garnered the attention of All For One, the most powerful villain in Japan. He is a very dangerous individual due to his Quirk, Overhaul, the handling he has on it, and his own lack of remorse. While in battle, Overhaul focuses on quickly dissembling his targets to kill them, or reshaping the terrain around him into a barrage of spikes to attack his opponent. He reshapes the ground to maneuver himself around the area, as well as counter incoming attacks. The ability to instantly rearrange his vicinity grants Overhaul multiple methods of dealing with his opponents, making him a massive threat from all ranges.[2]

In the past, when he recruited Kendo Rappa, a heavily experienced brawler, into the Shie Hassaikai, Kendo proposed that, in order to gain his servitude, Overhaul has to defeat him in battle. But just as Kendo prepared an attack, the Yakuza leader effortlessly disassembled, then reassembled Kendo. Even after Kendo become a member of the Eight Bullets, Overhaul was challenged by him 5 times, and swiftly overhauled and defeated the brawler with each attempt. When he first encountered the League of Villains, Overhaul was able to instantly destroy Magne, as well as the left arm of Mr. Compress, both of whom had the mettle to attack the Yakuza leader.

During the Shie Hassaikai Raid, Overhaul and his subordinates Hari Kurono, Shin Nemoto, and Deidoro Sakaki were encountered by Mirio Togata, a U.A. High School student worthy of the No. 1 Hero spot, who swiftly dealt with the latter two Hassai Group members before facing off against Hari and Overhaul in another 2-on-1 fight. At the beginning of the fight, Hari was incapacitated, while Overhaul temporarily held his own against Mirio, but was soon overwhelmed by The Big 3 member's top-tier prowess, which Overhaul himself noted was above his own abilities. Overpowered, Overhaul gave a defeated Shin Quirk-Destroying Bullets to depower the intangible hero which was a success. However, Overhaul still found himself on the defensive from Mirio's fighting spirit and brute strength, until he was finally capable of using reassemble spikes to immobilize and injure Mirio to a sufficient extent. Before Overhaul could finish off the depowered Mirio, Izuku Midoriya and Sir Nighteye arrived on the scene, with the One For All inheritor surprising the Yakuza leader with a One For All: Full Cowl smash.

With arrival of Izuku and Nighteye, Overhaul realized his plans were at risk of failing, so he went as far as to merge with Shin, and after doing so, Overhaul himself became monstrous in terms of appearance. This transformation granted Overhaul increased power, heightened speed, access to Shin's Confession Quirk, and an additional set of arms through which the amalgamated Yakuza leader can activate his original Quirk, showcasing a higher magnitude of control of the said power.[4] Overhaul's merged power allowed him to eventually overpower Sir Nighteye, critically injuring the former sidekick of All Might as a result, and effortlessly contend with Izuku, who raised his One For All output to 20%.

  • Enhanced Agility: Overhaul was challenged by Kendo 5 times, and each of those time, Kendo lost despite his prowess. This implies that Overhaul possesses his own degree of high speed and reaction time in order to accomplish this feat, as his Quirk requires him to touch his opponent for it to take effect. His fast reaction time is also shown when he was able to evade Mirio's punch, although he was left with a scratch on his face.
  • Enhanced Durability: Overhaul has great durability as he was assaulted by several of Mirio's punches and was able to take them as well as remain fully conscious despite still receiving bad injuries, whereas a simple attack from Mirio was enough to knock out and badly injure Deidoro and Shin, two of the Eight Bullets to the point where they could no longer fight. Later on, he was able to survive punches from Izuku who was wielding One For All at 100%. Overhaul also showed little reaction to having both of his arms destroyed by the League of Villains, albeit he still despaired over losing his two limbs.

Genius Intellect: Overhaul is an extremely intelligent person, with inventive, strategic, and tactical wits. The most noteworthy aspect of his intelligence is the Quirk-Destroying Drug he created from the DNA of Eri, whose Quirk, Rewind, can rewind a target onto a previous state. Following the Yakuza tradition of covering the trails of their crimes, Overhaul cleaned up his illegal actions by disassembling his targets first, taking what he needed from them and restoring their bodies to perfect condition in the end, thus avoiding incriminating evidence of violent assault from being left behind.[9]

During his brash encounter with the League of Villains, Overhaul knew that at least one of its members would attack him with a Quirk, so he preemptively had a sniper, equipped with experimental Quirk-Destroying Bullets, set as a precautionary measure. A measure that was proven very necessary as Mr. Compress lunged at the Yakuza, only to have his Compress Quirk temporarily erased.

  • Leadership Skills: Being the leader of the Hassai Group, he is a very organized person that can factor in the abilities of multiple people in order to initiate coordinated, and well-planned attacks. An example of this was when he suggested that Twice and Himiko Toga reveal their Quirk capabilities so that they can prep for the impending arrival of heroes. Overhaul had carefully set various members of his Hassai Group on different levels of the Shie Hassaikai Compound, all in attempt to slow down the heroes so that Overhaul can make his escape with Eri.


Overhaul Disassemble

Overhaul activated.

Overhaul (オーバーホール Ōbāhōru?): Kai’s Quirk grants him the ability to disassemble anything he touches, as well as reassemble it in any configuration he desires, effectively giving him full control over matter.

He can disassemble people to kill them or reassemble them to heal their wounds. He can also do this to himself and even merge his body with others; even allowing him to use their Quirks, such as Shin's Confession and Rikiya's Vitality Stealing. He can also apparently regenerate his limbs without having to make contact with himself and can reform and reshape their bodies any which way he wants.

In battle, Kai can freely manipulate his surroundings. He can modify the ground to maneuver himself and reshape the area into a state that is advantageous for him and harmful for his opponents. By touching his targets, he can completely blow their body apart, whether it be a limb or the entirety of it.

After Mr. Compress and Tomura destroyed his arms, which are also his Quirk Factor, Kai is currently unable to use his Quirk.


3/6 C
4/6 B
5/6 A
5/6 A+
6/6 S+
Kai's stats, according to the Ultra Analysis Book


Plague Mask: Kai has always worn a mask. Since being under the Hassaikai, Kai normally wore a simple black mask. After becoming a villain, Kai took to wearing his signature plague doctor mask that represents his efforts to cleanse the world of "hero disease".

Gloves: Kai always wears a pair of white plastic gloves. This helps prevent him from getting his hands dirty, and normally removes his gloves before using his Quirk. He wears them ultimately to avoid breaking out into hives.

Battles & Events

Battles & Events

Chapter Appearances

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 Debut
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 Absent
Shie Hassaikai Arc
122. A Season for Encounters Absent
123. Unrivaled Absent
124. Trouble Ahead!! Episode: Work Studies Appears
125. Overhaul Appears
126. Open Up, World Absent
127. Sir Nighteye and Izuku Midoriya and Mirio Togata and All Might Absent
128. Boy Meets... Appears
129. Eri Appears
130. Listen to the Truth Mentioned
131. Fighting Fate Appears
132. The Plan Appears
133. Catch Up, Kirishima Absent
134. Let's Go, Gutsy Red Riot Absent
135. An Unpleasant Talk Fantasy
136. Close at Hand!! Flashback
137. Restraint!! Appears
138. Go!! Appears
139. Shudder! The Underground Labyrinth Mentioned
140. Suneater of the Big Three Absent
141. Hassaikai: Behind the Scenes Flashback
142. Shield and Shield, Spear and Shield Mentioned
143. Let’s Rumble, Rappa!! Mentioned
144. Red Riot, Part 1 Absent
145. Red Riot, Part 2 Absent
146. Temp Squad Appears
147. Twoga!! Flashback
148. The Anguish of Young Twoga Mentioned
149. Don't Get Mad, Irinaka Appears
150. Mirio Togata Appears
151. Mirio Togata!! Appears
152. Lemillion Appears
153. Transform! Appears
154. Unforeseen Hope Appears
155. Saviors, the Saved and a Hero's Place Appears
156. The Power of Those Saved Appears
157. Infinite 100 Percent Appears
158. Chisaki's Warped Compassion Appears
159. It's Over!! Appears
160. Expressway Appears
161. Bright Future Mentioned
162. Suitable One Absent
U.A. School Festival Arc
169. School Festival Absent
170. With Eri Pictured
171. Gentle and La Brava Absent
172. Prepping for the School Festival Is the Funnest Part (Part 1) Absent
173. Prepping for the School Festival Is the Funnest Part (Part 2) Absent
174. Golden Tips Imperial Absent
175. Morning, the Day Of Absent
176. Deku vs. Gentle Criminal Absent
177. At the Construction Site Absent
178. The Woman Called La Brava Absent
179. School Festival Start!! Absent
180. Unbeknownst Absent
181. For Someone Else Absent
182. Let It Flow! School Festival! Fantasy
183. Festival All Day Long!! Absent
Joint Training Arc
194. Cold Skies Over U.A. High! Absent
195. Clash! Class A vs. Class B! Absent
196. Make It Happen, Shinso!! Absent
197. Quaotic Quirkstravaganza Absent
198. Known Where You Stand When It Counts!! Absent
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 Absent
210. The One For All Dream Absent
211. That Which Is Inherited Absent
212. That Which Is Inherited, Part 2 Flashback
213. Realm of Souls Absent
214. Our Brawl Absent
215. Final Face-Off! Midoriya vs. Shinso! Absent
216. Class A vs. Class B: Conclusion Absent
217. The New Power and All For One Absent
Meta Liberation Army Arc
218. The Meta Liberation Army Absent
219. Go! Slidin' Go! Absent
220. My Villain Academia Absent
221. Memento from All For One Absent
222. Tomura Shigaraki: Distortion Flashback
223. Cockroaches Absent
224. Revival Party Absent
225. Interview with a Vampire Absent
226. Bloody Love Absent
227. Sleepy Absent
228. Wounded Soul Absent
229. All It Takes Is One Bad Day Absent
230. Sad Man's Parade Absent
231. Path Absent
232. Meta Abilities and Quirks Absent
233. Bright Future Absent
234. Sense Destruction Absent
235. Tenko Shimura: Origin Absent
236. Tenko Shimura: Origin, Part 2 Absent
237. Tomura Shigaraki: Origin Absent
238. Liberation Absent
239. Successor Absent
240. Power Absent
Paranormal Liberation War Arc
253. Shirakumo Absent
254. You Could Be More of a Hero than Anyone Absent
255. Hero Hopeful Absent
256. The High, Deep Blue Sky Absent
257. Pass It Forward, to Whomever Absent
258. Friends Absent
259. A Quiet Beginning Absent
260. Life's Work Absent
261. High-Ends Absent
262. Mirko, the No. 5 Hero Absent
263. I Wanna Be With You Guys!! Absent
264. One's Justice Flashback
265. Villains and Heroes Absent
266. Happy Life Absent
267. Flames Absent
268. Scramble! Absent
269. The Three of Us Absent
270. Inheritance Absent
271. Dark Cloud Absent
272. Good Morning! Absent
273. The Thrill of Destruction Mentioned
274. Search Absent
275. Encounter, Part 2 Absent
276. You Cheated...! Absent
277. Who...? Absent
278. Disaster Walker Absent
279. League of Villains vs. U.A. Students Absent


  • Kai's name contains the kanji for "govern, regulate, administer" ( () chi?), "promontory, cape, spit" ( (さき) saki?) and "revolve, return, curving" ( (かい) kai?).
    • His first name notes his Quirk, Overhaul, that grants him the ability to disassemble and reassemble anything that he touches.
    • The "chi" in his surname has different meanings attached:
      • It could mean (to treat, to cure disease) how he believes everyone is sick, obsessed with finding a cure.
      • (To research, to specialize in a topic) noting his research on destroying Quirks.
      • (To punish, to discipline, to teach someone a lesson) referring to how he treats Eri as a subject for his bullets and force her to obey through intimidation and how he was hoping to use the Quirk destroying drugs to control society through fear.
      • (To exterminate, to kill) seen several times that he used his Quirk to kill others.
  • He is a B-Rank Villain.[1]
  • Overhaul and Tomura have several similarities:
    • Both characters wear plain clothes and a coat, but also have unique masks.
    • Both possess a nervous tic that results in them scratching their own body.
    • Both are succeeding leaders in their respective organizations, after a previous leader was toppled.
      • Both had a close relationship to their own previous leader, having been essentially adopted by them.
    • Both of their Quirks have similar attributes:
      • Both require direct contact with their hands to touch their target for their Quirks to work.
      • Both Quirks are destructive in nature to their enemy.
  • Overhaul's first encounter with the League of Villains bares similarity to Stain's first encounter with the league.
    • Both were committing their own acts of violence before being approached by a member of the league.
    • Both had some level of interest in the league before revoking their interest after realizing the league's limits, which led to a conflict between them.
    • Both ended their meetings in bad taste with the league.
    • Both stated that the league had some form of potential and would see how that grows. Though for Overhaul, that potential is more for his own motives.
  • In the Fourth Popularity Poll, Overhaul placed 25th.
  • In the anime, Kai's skin is seen to break out in hives whenever his mysophobia is triggered.


  • (To Izuku Midoriya) "When someone lays a finger on me, I can't help but feel the need to cleanse myself."[10]
  • (To Eri) "You were born to destroy people."[2]
  • (To Eri) "Each and every one of your actions kill people. Yours is a cursed existence."[2]


  1. 1.0 1.1 My Hero Academia Official Character Book 2 Ultra Analysis.
  2. 2.0 2.1 2.2 2.3 My Hero Academia Manga: Chapter 151.
  3. My Hero Academia Manga: Chapter 125 (p. 3).
  4. 4.0 4.1 My Hero Academia Manga: Chapter 153.
  5. My Hero Academia Manga: Chapter 157.
  6. My Hero Academia Manga: Chapter 115.
  7. My Hero Academia Manga: Chapter 152.
  8. 8.0 8.1 My Hero Academia Manga: Chapter 160.
  9. My Hero Academia Manga: Chapter 135.
  10. My Hero Academia Manga: Chapter 154.

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