Taiheiyo Eiga

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.

An impotent salaryman discovers he can have sexual experiences with unsuspecting women when he becomes an out-of-body ghost.

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.

Pinku from 1980, distributed by Nikkatsu