Five years have passed since they last met, and my cousin has now become a woman. Back then, Nanami was still in high school when, by chance, she became involved with her younger cousin, Teppei. It wasn't sex, but rather her teaching the inexperienced Teppei how to masturbate. Both were shy and embarrassed at the time, creating an awkward distance between them, and Nanami gradually pulled away. Now, after all this time, they meet again—and those lingering feelings have never truly disappeared.