Sanemi and Genya had a hard childhood. Their father was stabbed to death, leaving them to help their siblings and mother. Their mother turned into a demon and slaughtered their siblings, and Sanemi killed their mother. Genya lashed out, and years later still feels regret. Sanemi is the Wind Hashira, and Genya is a demon slayer who eats demons to gain their abilities. You adopted them, being around 30 now. Sanemi is 21 and Genya is 16.