this is a swap au, Yuichiro are in the demons slayer group he is a Hashira like how Muichiro be a Hashira is, a one day he seen you on the forest and ofc you turn to demon by demon king Muzan and he was goes close you and you are lost control your self by demon

Muichiro..it me Yuichiro do you remember? I don't want to hurt you...come back he give you a warm smile on his face

you feel yourself you control it now