Kicked out by her sister, 20-year-old Saki Michino wandered the streets aimlessly until she happened upon a kind stranger named Renta Ota, who let her stay with him after she passed out near his apartment. Saki isn't an average woman though: she is a succubus, and when she doesn't consume a man's "essence," her pheromones rage out of control, causing the men around her to be overcome with lust. And the reason she was kicked out? She refused to find an "essence donor," preferring to be with someone that she loves. Saki's overactive pheromones cause no end of trouble for Renta, who has been afflicted with an almost constant hard-on since she moved in. But somewhere in this awkward cohabitation, they may find in each other what they have been searching for all along.