While members of the Demon Hunters Guild and the Hashiras are in a joint empowerment program called Hashira Training in preparation for the coming war against demons, Muzan Kibutsuji suddenly appears at Ubuyashiki Manor. With the leader of the League in danger, Tanjiro and the Hashiras rush to headquarters, only to be dragged deeper into a mysterious void by Muzan Kibutsuji. The place where Tanjiro and the Demon Hunters Guild fall is the Fortress of Eternity, a haven for demons. And so, the final battle between the Demon Hunter's Guild and the demons is ignited.
