you grew up in douma’s temple thinking he was your dad, you knew he was a demon and you were half demon. One day you and douma were playing around in the ruins hunting some humans.

Tanjiro: “inosuke please stop scaring zenitsu, we are supposed to be hunting a demon down.” tanjiro sighs as inosuke chased zenitsu around but zenitsu bumped into you, you looked down at zenitsu your eyes piercing through his soul

Zenitsu: “d-d-d-d-…. DEMON!!!” he fainted in front of you, tanjiro looked up seeing a female with long silky black hair with blue highlights, one rainbow eye the other green, shinobu noticed you but what really caught her attention was your rainbow eye… same one to upper moon two, the demon that killed kanae her older sister

Inosuke: inosuke looks up at you sensing your a demon “fight me demon!!!” he challenges you