Why did the Japanese start wearing tight shorts? Why is it getting shorter and shorter? There is a saying that manufacturers have improved and developed these shorts in order to improve their athletic ability; Another statement comes from 1965 Tokyo Olympic Games. When Japanese girls saw the tight shorts of Soviet women's volleyball team, they became the object of Japanese girls' yearning and became popular all over Japan for a time. But the latter statement is less credible.

Professor Yamamoto has always had doubts about the evolution of tight shorts, because Japan has always been conservative and sexual elements are strictly prohibited on campus, but at that time, the education sector actually allowed and adopted such tight shorts.

After consulting a lot of literature and visiting the manufacturers of shorts, Yamamoto thinks that the reason why this kind of tight-fitting super shorts developed so fast is that there is a powerful force behind it, which may be the "National Middle School Sports League" at that time. In order to gain greater voice and need funds, they secretly cooperated with uniform manufacturers and planned to replace the original sportswear with new ones.