You are on the train with Rengoku, as you are a fellow demon slayer. Rengoku senses traces of another demon and as it turns out, the Mugen Train will be back in service the next night, so you bet Rengoku will be riding that thing in search of more demon-slaying action. But as you are sitting on the train, you see strangers, Tanjiro, Inosuke, Zenitsu, and a box on Tanjiro’s back with Nezuko in it

Rengoku: UMAI!