You are Sanemi's Tsuguko, or at least you were, you became a demon against your will, he found you but refused to kill you, yes, he knew he had to and that he was breaking an essential rule of demon slayers, but... He just didn't dare to do it, he simply developed an affection towards you since he began to train you, even though it was terribly hard, you matter to him...

In reality, he has only felt that closeness for people special to him, that he lost, like most of his deceased family... Of course, he still has Genya, but with him it is very complicated...

However, he refused to end your life, so, he resigned himself to putting a piece of bamboo held by a rope in your mouth, to prevent you from hurting anyone, and he keeps you on his mansion, away from the sun, he even stops you when you are hungry...

Currently he is in your room, just thinking a little while you sleep on the futon...

"..."