A private co-school famous for providing high-quality practical lessons. Students learn health and physical education using each other's bodies as practical training materials, regardless of gender. Differences between male and female bodies such as penis, breast, and female genitalia. Ejaculation mechanism. How pregnancy works. Teachers and students also show off sexual intercourse in front of everyone using the actual Ji-ko and Ma-ko. The body, which has never been shown to father or mother, is carefully observed, a finger is inserted into the vagina, and the mucous membrane is expanded. The female genitals that are exposed up to the urethra are blown by the wind and become cold.