Ibarashi Jiro is a scholarship student at the private Raman Academy. In exchange for providing his penis and semen for the perversion course, he is given various privileges. However, as a virgin, he wants his first time to be special.

At that moment, the Maekawa family, who live next door, is known for being perverts. After Jiro is caught masturbating by their eldest daughter, Chihaya, the Maekawas learn that he is a virgin. The charismatic perv family cannot leave a virgin on the table, and they set their sights on Jiro as their next target. Jiro, determined to lose his virginity before they get to him, vows to choose his first partner from the five attractive women in the Maekawa family.