In the guise of a demon, Akutsu Masatora blends into a human high school, seeking allies for Hell in its eternal battle against the angelic forces of Heaven. His attention is drawn to Lily Amane, a recent transfer student whose allure captivates him, leading him to consider her for recruitment. Yet, as Akutsu delves deeper, he uncovers unexpected layers to Lily, forcing him to question his loyalties as he navigates newfound emotions entwined with the enemy he was meant to combat.