In the sweltering summer of 202X, a crisis looms over the demon realm. The souls that have long fueled their magic are drying up. Why? Because humanity has become more ruthless than the demons themselves, making the old contract of selling one's soul for demonic aid utterly obsolete.

Faced with a devastating unemployment crisis, demons are forced to adapt, retraining as "Incubi"—creatures who can feed on life force without a contract. The protagonist, Ufir, embarks on this path, but the transition is anything but smooth. As he attempts a dangerous shortcut to become an Incubus, his plan is thwarted by a man who is as unyielding as he is righteous: the detective, Cheolho.