"Practical sex education," which was introduced as part of measures to combat the declining birthrate, is sex education in which teachers directly teach using their own bodies. However, some students are unable to keep up with the lessons. To ensure that they won't have trouble having children in the future, the beautiful private tutor Matsuna visits the home of an adolescent virgin boy to give him direct sex instruction! The first time, he watches the teacher have sex with a male teacher. The second time, the teacher takes the lead and has raw sex to make a baby, resulting in the first implantation and pregnancy!