Fourteen-year-old Iruma Suzuki's luck couldn't get any worse. Unable to refuse his parents' dangerous demands, he has always obeyed, even when it meant risking his life. However, everything changes when his parents strike a deal with Sullivan, a powerful demon, trading Iruma's soul. To Iruma's surprise, Sullivan only wants to be like a grandfather to him, offering care and enrolling him in the demon school Babyls. Concealing his human identity becomes Iruma's top priority at school, where blending in is crucial. Yet, as he navigates this new world, Iruma uncovers secrets about his own extraordinary nature and realizes the demons around him are more than they seem.