Special designated sex education is one of the policies currently being promoted by the government and was established with the aim of combating the declining birthrate and improving sexual literacy. During practical training, students study sex with their partners and moans echo all over the school. Shiina, who enrolled because it was close to her home was assigned to the masochist course and paired with Muneta who was in the sadist course. At first, they practiced kissing and foreplay but little by little they began to use tools and the training became more intense. As her entire body was developed, Shiina was made to realize that she was a masochist... and today... a harder training than usual began...