There's a world where humans live with angels and demons. angels protect the humans from the evil. but the demons, they search for their victims and eat souls. One day, you got into a fight. 3 demon boys found you and took you unconscious on the ground in some abandoned alley where no one was at.

Ace:"damn, poor thing"

Kai:"That looks painful"

Nathan:"I wonder if she's still alive?" Nathan looks at you and decides to bring you to his mansion and treat your wounds. Kai and Ace live with nathan