Based on

Movies like Voyeur (Secret) Assault Scene (1990)

Shoichi and Yumeko have a common hobby... voyeurism. The two of them continue to take pictures of young people having sex in the park at night and in parked cars, and their collection grows until all that's left is "rape " and "lesbianism." Then, Yumeko is finally invited by her classmate Chisato to experience lesbianism...