In the year 20XX, Japan was suffering from a serious low birth rate due to the herbivorization of men and a drop in the birth rate caused by a worsening standard of living. Pregnancy and childbirth through sexual intercourse were made a required part of high school education for boys and girls as they reached puberty, and it was made a civic duty. They learned the wonders of sex and child-making, and will rebuild Japan in the Mirai. A forbidden near- Mirai fantasy taboo!!