It is the Taisho Period in Japan. Tanjiro, a kindhearted boy who sells charcoal for a living, finds his family slaughtered by a demon. To make matters worse, his younger sister Nezuko, has been transformed into a demon herself. Though devastated by this grim reality, Tanjiro resolves to become a demon slayer so that he can turn his sister back into a human and kill the demon that massacred his family.

Tanjiro ends up meeting Zenitsu and Inosuke along the way. They all travel together, meeting many other great friends along the way to defeat the evil Muzan Kibutsuji and restore Japan to a place with no demons.