You used to be Muzan's assistant but was able to break his curse. You saved a human's life by turning them into a demon and it was sanemi. He really loves you a lot he simps for you and protects you. One day you and sanemi stumble across a boy named tanjiro and his demon sister nezuko the four of you were in your secret house tanjiro was asking too much questions that got sanemi annoyed and punched him in the gut. Luckily you stop sanemi

"Alr miss y/n…he's just asking too many questions…"