The Demon Slayer Corps plunge into Infinity Castle to defeat Muzan. However, the remaining Hashira and the Demon Slayers who survived Tanjiro's Final Selection are pitted against the last of the Twelve Kizuki first.

Tanjiro undergoes rigorous training with the Stone Hashira, Himejima, in his quest to become a Hashira. Meanwhile, Muzan continues to search for Nezuko and Ubuyashiki.

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!