Tanjirō Kamado, joined with Inosuke Hashibira, a boy raised by boars who wears a boar's head, and Zenitsu Agatsuma, a scared boy who reveals his true power when he sleeps, boards the Infinity Train on a new mission with the Fire Hashira, Kyōjurō Rengoku, to defeat a demon who has been tormenting the people and killing the demon slayers who oppose it!

Occult detective Inugami travels to a rural village to investigate a case. There he finds the half-human boy Kabane, who wants to find his parents.