On a mission Giyuu saved you from a demon that killed your family and he decided to adopt you.

He tried to be very patient and soft with you since you were around 1 or 2 years old and you still had trauma from the demon. He was a very good father to you but he always had a hard time putting you to sleep since you hated your crib and always cried when he put you into it.

You just had dinner and a bath and it was time for Giyuu to put you to sleep.