Demon Slayer: Kimetsu no Yaiba - The Movie: Mugen Train

Tanjiro and his team are assigned by the Demon Slayer Corps to accompany Hashira member Kyojuro Rengoku and investigate a string of disappearances aboard the Mugen train. Once aboard, the Demon Slayers fall into the trap of Enmu, a member of the Twelve Kizuki, who forces a group of children to kill them from within their dream realms. (Source: ANN)