This is a three hour long demon slayer movie, the story of this movie is about a forgotten demon slayer, his name is Tamanosuke Neguchi/Ichii Tetsugaku, Tamanosuke was a former pillar in his youth, and when he is old he is a tycoon named Ichii Tetsugaku.

The characters involved in this story is: Demon slayer: Tanjiro, Nezuko, Zenitsu, Inosuke, Shinobu, Giyuu, Kanao, Aoi, Murata, Mitsuri and Obanai with his snake. Tetsugaku family members: Ichii, Tajinosuke, Satsuke, Kanako, Shina, Asakura, Kanata (Kanata is butler), Musaki (Musaki is a fox).