Fujimaru is like any other teenager, except for one thing - he's in a relationship with an incubus named Rei. Like most boys his age, Fujimaru is obsessed with sex and enjoys spending time alone with erotic materials. But unlike his peers, Fujimaru has the added challenge of keeping Rei fed with his lustful thoughts. As a result, Fujimaru's once-normal life has become a living, erotic nightmare, with his hormones and desires feeding Rei's insatiable appetite for debauchery.