It's not forced at all. This is the village's rule. In this remote village, adults still practice and teach sex to girls so that they won't be ridiculed when they go to the city—an unconventional and dark custom that still exists today! "Now, take off your clothes!" says the elder. Some students resist a little, but under pressure from the townspeople, they are told, "Everyone else is doing it," and the students participate... This is a form of sex education called "sex camp" that is still being practiced somewhere in Japan today.