Kazu Notus, a biology graduate student obsessed with finding the mythical "lewd elves," finally discovers one named Mana. As Kazu teaches the innocent Mana about her own body, their relationship quickly turns sexual. After meeting Mana's older sister, Tieru, Kazu learns that procreation is vital for their race, leading Tieru to demand that he take responsibility for Mana while the two sisters begin to compete for his attention.
After helping Tieru discover pleasure through a potent ancestral love potion, sensei finds himself committed to both elf sisters. The situation escalates when their mother, Mahnaria, arrives to test the effects of her aphrodisiac on him. Following an intense encounter, Mahnaria also decides to join the union, leaving sensei as the partner to an entire family of lewd elves.