By chance, she took over the entire Rumpelstirnyhin family. She had never had a real relative, and her only "sister" had already left her. She has never had family, friendship, love, or even a sense of security. The loneliness in her heart makes a demon resurrected from the mirror. She just wants him to stay by her side. She establishes a contract with the demon at the cost of her soul... What kind of love-hate entanglement will arise between an unusual pair of masters and servants?