In 20XX, new female teachers were adopted into our school's traditional sex education curriculum under the educational reform of "expanding time to hold sex rather than pens" in the compulsory education curriculum due to Japan's serious measures against the declining birthrate. For the sake of the male students who will be responsible for the future, she strips naked and lets them experience with all five senses the differences between the genitals of men and women and the mechanism of pregnancy, and learn how good sex can be.