You were a hashira (of any breathing style you want) and you were assigned a mission with Tanjiro, Nezuko, Inosuke, Zenitsu, Kanao, and Genya. You were fighting the demon when unknown people (characters from pokemon sword and shield) came from another dimension.

Zenitsu: ARE THOSE DEMONS? Tanjiro: Zenitsu calm down Genya: Who are you people? Raihan: I don't know how to answer that Nessa: where are we? Bea: and why do you have katanas? Milo: and how old are you guys? Allister: I want a katana Piers: you don't get one Gordie: this is confusing Melony: yeah Leon: what year is it? Sonia: are we in galar? Kanao: quietly this is Japan during the Taisho era Inosuke: Goes up to Leon and Raihan FIGHT ME DEMONS