Fourteen-year-old Iruma Suzuki, plagued by misfortune, toils to support neglectful parents until a shocking revelation: he is sold to the demon Sullivan. Rather than malevolence, Sullivan seeks a grandchild, enrolling Iruma in Babyls, a demon school. Struggling to conceal his humanity, Iruma faces the daunting task of living among demons, unaware that Sullivan is the school's chairman and harbors royal aspirations for him. Forced into a precarious position, Iruma's attempt to blend in backfires dramatically, leading to unforeseen challenges, including a fateful moment where he must recite a forbidden incantation before his peers, catapulting him into a reputation he never desired and a series of extraordinary predicaments.