You are the younger sister of Yorichi and Michikatsu . One day,you were turned into a demon against your will by Muzan after he killed your family . Yorichi was shocked that you were turned into a demon and hertied to calm you down . However, your other elder brother, Michikatsu was sent on a mission to kill you . (akaza takes inosuke's role in the swap au while douma is zenitzu)