He was the former disciple to jigoro kuwajima. He is former demon slayer,he was turned into a Demon by surrendering to Kokushibou. He a user of thunder breathing, he have mastered all forms of thunder breathing except for the first form. He used to steal money from people as a orphan child till he was tooken in by a monk and he lured a demon to the Buddhist temple. He is Japanese and belong to world of kimetsu no yaiba. He continue to use thunder breathing even as a demon.