I offered above, but nothing came of it...
The fantasy I have explored often (in my head) is that the final two years of high school are used for detailed sex education and more.
Through this time, students are used as specimens for each other's education, and in time all students are assigned into small groups, where each of the girls has supervised interactions with the boys, in order to be fertilised and have babies.
Teachers are on hand, to help them learn about each other's bodies, and the mechanics of sex to achieve orgasms and when her time is right, fertilisation.
It is hoped that all the girls have a child that year... as by the end of the year, every girl is sterilised to manage population growth.
Of course, the year is a "live in" year, and the pregnancies are monitored through the ongoing biology classes... and births are undertaken in the school too.
Most get used to very little privacy, and lots of examinations and investigations by the other students.