After Ophelia Grimm's mother suddenly dies and she receives the family necromancer magic, Ophelia and her sister Genevieve learn that their mother had outstanding debts, and their family manor was the collateral. When Genevieve enters into Phantasma, a deadly game through the 9 Circles of Hell in which the winner can ask a Devil for whatever their heart desires, Ophelia follows her, determined to force her to forfeit. But once inside, Ophelia learns that she can't see her sister until level 7 and must survive the Devil's Manor until then.