Kai Chisaki, also known by the villain name Overhaul, is the Yakuza Captain of the Shie Hassaikai.
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". 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.
Kai's Quirk "Overhaul" 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. Kai 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
