Pinku from 1979.

In a remote rural town lived two men: Gyoromatsu Hashishita, renowned as a master of nighttime visits, and Senkichi Nitta, a novice. They would sneak into various houses and enjoy having intense affairs with all sorts of women around the town. One day, as usual, Senkichi was hurrying towards his new target house under the moonlight, but he was restless. This was because his target for that night's visit was Oyuki, the woman he was deeply in love with. A romantic porno depicting the fate and hard-ons of these genius nighttime visitors.

Three female college students all need extra credit in order to graduate. So they convince an assistant professor into helping them with a three day cram course… in immersive sex studies.

A young and beautiful female instructor. While she has a physical relationship with a guard, she also serves as a spy for the warden. She disguises herself as a prisoner and sneaks into the cells, cleverly finding out the prisoners' secrets and reporting them to the warden. As a result, a thought criminal commits suicide, and a colleague who became involved in lesbian relations with a female prisoner is punished.

A beautiful bride came to the old house. No one knew her past. Life with Husou Genzo was happiness itself... The younger brother, who had returned home, was once the bride's lover. She seems to keep in touch with her brother-in-law... However, they are discovered by the villagers.

Pink film distributed by Toei New Porno.

Pink film from Toei Central.