This article is about the character. For this character's Quirk, see Overhaul.
Kai is a pale man of narrow build with short, shaggy auburn hair, parted to the right. 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, 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 once the war ends. Following his imprisonment in Tartarus, Kai's hair has become a bit longer and now has some stubble.
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 with a thick purple fur collar and white lace-up sneakers with tan soles and no socks. 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, are his most distinguishing features.
After fusing with Shin Nemoto, Kai 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.
After fusing with Rikiya Katsukame, Kai's lower body is fused into a monstrous stone structure, protruding multiple appendages each equipped with clawed hands. Kai's upper body is the same but lies within the mouth of the structure, and his upper jaw has Rikiya's mask.
Kai is a mysophobic, antisocial sociopath who is 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, Kai 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". Kai 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. Kai 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 All For One's downfall. In spite of this, Overhaul's values are noted to be paradoxical, particularly his overreliance on his Quirk that he happened to name himself after.
As the leader of the Shie Hassaikai, Kai 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, Kai 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.
Kai is very germaphobic 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 Kai's person, he will start developing hives and lose his usual composure, becoming increasingly unhinged as a result. In drastic circumstances though, Kai 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.
Kai 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.
The only person Kai has ever shown concern for is the former boss of the Shie Hassaikai, who rescued him from the streets at a very young age 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. Ironically, this makes his ideals about family much more personal than any other members of the organization.
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, intending to bring his boss out of his coma after he completed his plan.
In the end, Kai's failure to recognize others and his own obstinate nature resulted in his downfall. As noted by Tomura, even though Kai's goal is to erase Quirks and restore the yakuza to power, he hypocritically himself used a Quirk to achieve that plan. 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, screaming as the reality of being unable to bring the boss out of his coma hit him.
As seen by the time of Tartarus' mass riot and breakout, Kai's imprisonment and the comatose status of his boss has left him as a shell of his former self, being rendered to a near-catatonic state and being unresponsive to everyone, anyone and everything around him. This is seen where he had little to no reaction of the mass riot during the Tartarus prison break and later showed no reaction to the appearance of Tomura Shigaraki and All For One, only being able to mumble the words "Old Man", likely referring to his boss and father figure. The only thing Kai cares about is reuniting with his boss, mumbling on how he wants to see him again even when in close proximity to danger.
Kai is even shown crying out of regret while begging to apologize to the boss. While he still hates Izuku (despite the latter having saved his life) and holds no regret for his treatment of Eri, he did agree to make amends with Eri but only so he could save his boss.
Overall Abilities: Prior to his dismemberment, Kai 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, Kai focuses on quickly dissembling his targets to kill them, or reshaping the terrain around him into a barrage of spikes to attack his opponents. He reshapes the ground to maneuver himself around the area, as well as counter incoming attacks. The ability to instantly rearrange his vicinity grants Kai multiple methods of dealing with his opponents, making him a massive threat from all ranges.
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, Kai 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, Kai was challenged by him 5 times, and swiftly overhauled and defeated the brawler with each attempt, despite Kendo's prowess. This implies that Kai 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.
During the Shie Hassaikai Raid, Kai 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 Hassaikai Group members before facing off against Kai and Hari in another 2-on-1 fight. At the beginning of the fight, Kai evaded one of Mirio's punches, although he was left with a scratch on his face, before Hari was incapacitated. Kai was left temporarily holding his own against Mirio, but was soon overwhelmed by The Big 3 member's top-tier prowess, which Kai himself noted was above his own abilities. However, Kai still found himself on the defensive from Mirio's fighting spirit and brute strength, until he was finally capable of using reassembled spikes to immobilize and injure Mirio to a sufficient extent.
With the arrival of Izuku and Nighteye, Kai was forced to merge with Shin. This transformation granted Kai increased power, heightened speed, access to Shin's Confession Quirk, and an overall monstrous appearance equipped with an additional set of arms through which the amalgamated Hassai Group leader can activate his original Quirk, showcasing a higher magnitude of control of the said power. Kai's inflated power allowed him to eventually overpower Sir Nighteye, critically injuring the former sidekick of All Might, and contend with Izuku, who was soon forced into raising his One For All output to 20%. After being spontaneously defused by Eri, Kai made a last-ditch effort to prevail against the heroes, by fusing with Rikiya Katsukame, acquiring an even greater degree of power, and a more atrocious form. While he did engage Izuku, Kai began struggling against the hero's "One For All: Full Cowl - 100%", until he was completely outmatched and defeated.
- Enhanced Durability: Kai has great durability as he was assaulted by several of Mirio's punches and was able to endure them as well as remain fully conscious despite still receiving bad injuries. This is an impressive feat, as a single attack from Mirio is occasionally enough to incapacitate somebody into submission. Later on, he was able to survive punches from Izuku who was wielding One For All at 100%. Kai 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.
- Enhanced Reflexes: Overhaul possesses quick reflexes sufficient enough to quickly and consistently defeat Kendo Rappa at close range who is said to punch like a hail of bullets. Overhaul also displayed enough speed to dodge Mirio's attacks.
Genius Intellect: Kai is an extremely intelligent person, with inventive, strategic, and tactical wits. Following the yakuza tradition of covering the trails of their crimes, Kai 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. The most noteworthy aspect of Kai's intelligence is the Quirk-Destroying Drug he created from the DNA of Eri, whose Quirk, Rewind, can rewind a target into a previous state. Alongside the drug, Kai also developed an antidote serum, which can nullify the Quirk-neutralizing effects and restore the victim's Quirk. With these two products in his possession, Kai planned to resurrect the glory of the Shie Hassaikai, and the yakuza in general, by using the drug and the serum as a way to accumulate large financial resources, as well as a tool to induce fear into the modern Quirk-dependent population. The drug was intended to be sold through the black market to villains, who would use them on Pro Heroes and after a while, the yakuza would distribute a serum that would undo the damage done and restore the lost Quirks to the heroes. These products would be at a high price. Therefore, with the villains having the Quirk-Destroying bullets, the heroes having the serum, and Eri in the middle, the Shie Hassaikai can monopolize control of the market, earning massive profit and eventually emerging from the shadows.
During his brash encounter with the League of Villains, Kai knew that at least one of its members would attack him with a Quirk, so he preemptively had Hari act as 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 Kai, only to have his Compress Quirk temporarily erased. When he battled Mirio Togata and observed his Permeation Quirk, Kai altered the terrain to block the hero's exit route, knowing that Mirio can't use his intangibility to escape without leaving Eri behind. Shortly before the rest of the Nighteye Squad's arrival, Kai discreetly used his Quirk to heal Hari, all so the latter can pretend to be unconscious, blindside Eraser Head, and overtake the Erasure Hero. After defeating Sir Nighteye, Izuku arrived on the battlefield stronger than ever, making Kai realize the One For All inheritor was holding back before. Since he merged with Shin and gained access to the latter's Confession Quirk, Kai employed the same guerrilla warfare tactics the con artist uses in order to psychologically lure Eri back to his side, which was nearly successful had it not been for Izuku's interference.
- Leadership Skills: Being the leader of the Hassaikai 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. Kai had carefully set various members of his Hassaikai Group on different levels of the Shie Hassaikai Compound, all in an attempt to slow down the heroes so that Kai can make his escape with Eri.
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.
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 rubber 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|
- Kai's name contains the kanji for "govern, regulate, administer" (
治chi?), "promontory, cape, spit" ( 崎saki?) and "revolve, return, curving" ( 廻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.
- 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.
- Kai purposefully kept the scar that Magne gave him as a way to admit his fault in killing her, but also to keep an air of intimidation around the other League members.
- As a child, Kai is voiced by Caitlin Glass in English, who also voices Mina Ashido.
- Kai is the second villain whose villain name is the exact same as his Quirk after All For One.
- Kai likes the Hassaikai.
- (To Izuku) "When someone lays a finger on me, I can't help but feel the need to cleanse myself."
- (To Eri) "You were born to destroy people."
- (To Eri) "Each and every one of your actions kill people. You are a cursed existence."
|Leaders||Overhaul • Chronostasis • Mimic|
|Eight Bullets||Deidoro Sakaki • Hekiji Tengai • Kendo Rappa • Rikiya Katsukame • Shin Nemoto • Soramitsu Tabe • Toya Setsuno • Yu Hojo|
|Locations||Shie Hassaikai Compound|
|Guards||Briareos • Gyges|
|Convicts||All For One • Dictator • Kurogiri • Lady Nagant • Moonfish • Muscular • Overhaul • Stain|