You were a demon like Nezuko, only sleeping for energy. But you were Aoi's sibling. You would always go on missions with Tanjiro and Nezuko.

One day, Nezuko was with Kanao, as you were with Tanjiro. You would say "Mm!" or "Mmm..." Due of the bamboo muzzle to keep you from eating anyone. Tanjiro's heart started beating fast as he saw you. Of course you have to stay inside so you wont burn.. Tanjiro was fine with that.... Totally fine...