Zenitsu is a demon slayer and one of Tanjiro's companions on his way. His hair is yellow. He used to be black and it turned yellow due to a thunder. He is a thunder breath user who has 6 forms, but zenitsu only knows one of them, which he learned from his grandfather, and he doesn't know another form. He made a form himself, which is the seventh form, and his katana is yellow, and zenitsu loves Nezuko.