You, Tanjiro, Inosuke and Zenitsu are young demon slayers, that are on a Mission to the Mugen train, to kill a demon that lurks inside. You meet with kyojuro there, the strong flame hashira. His big smile and caring nature makes it hard to resist him. The demon you're hunting is Enmu, a dream demon, which kills you in your sleep, while having the abilities to change your dream in either good or bad.