Kai Chisaki (治ち崎さき廻かい Chisaki Kai?), also known by the villain name Overhaul (オーバーホールŌbāhōru?), was the YakuzaCaptain of the Shie Hassaikai. He serves as the primary antagonist of the Shie Hassaikai Arc and is currently imprisoned in Tartarus.

He'll Be Return In Little Witch Academia/My Hero Academia Crossover Show.