During the New Year's holiday break, the protagonist returns home and reunites with his childhood friend Momona, who has grown into an incredibly cute woman. Confiding about his inability to ejaculate inside his girlfriend, Momona offers to help him practice vaginal ejaculation. This favor escalates into passionate unprotected sex with multiple creampies. Throughout his stay, they engage in endless raw intimacy, turning friendship into intense desire in this drama of reunion and forbidden pleasure.