Hole in Underpants: Blue Strawberries (1990)

In this omnibus movie of four stories about teenagers there is a boy who lives next to a university women's dormitory and he checks them out constantly. He finds out about their relationship with men. He decides to forget about them and decides to date a class-mate. Next three boys want to rent a adult video, but cannot due to their age. Instead they make their own. They meet a girl who is a video store clerk. They fall in love. She also happens to be an actress. Next is a boy in a band who cannot play well as his mind is on a girl who is relocating. The said girl has a man on her mind too. In the fourth story, the world is upside down and the students teach their instructors.