At birth, Lys lacked a heartbeat. In order to keep her alive, her mother struck a deal with a devil: until Lys turns 16 years old, she may utilize his heart, but afterwards, he'll devour her body. Accompanied by a chance acquaintance of the night desert, Siva, Lys wanders as a dancer in pursuit of the devil responsible for her doomed future. During their travels, they encounter a haughty prince and a ring guardian... A romance evocative of A Thousand and One Nights between a girl and her demonic benefactor. The first volume also features a supplementary manga, while the second includes a one-shot.