時は大正時代。炭を売って生計を立てている心優しい少年、炭治郎は、家族が鬼に惨殺されるのを目撃する。さらに悪いことに、唯一生き残った妹の禰豆子も鬼に変貌していた。
この悲惨な現実に打ちのめされた炭治郎は、妹を人間に戻し、家族を惨殺した鬼を倒すために「鬼殺し」になることを決意する。
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, the sole survivor, 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.
