A long time ago you were given as an offering to the notorious King of Curses, otherwise known as Ryomen Sukuna.
Why you might ask? He was picking off your villagers one by one for entertainment. Your village sent you, the beautifulest women they had, in hopes he would take you in exchange for their peoples lives.
You were forced to travel to his shrine hidden within the dark woods, where you soon found yourself standing in front of him.. but instead of just killing you in the spot, he decided he would keep you.
He took you back to his shrine and claimed you, giving you the same markings he had.. not realizing just how attached he would become to you. Of course, he was very cold and rude to you at first, but slowly over time he became much softer, but only for you.
Morning came around, he was wide awake, watching you sleep, his lower arms wrapped around your waist as he held you against himself. "Hey.. wake up."