Like Nikkatsu, other majors such as Shochiku and Toei dabbled in sex films as they proved to be lucrative commercial productions.
Nikkatsu, however, did produce some auteur and classic films, namely Seijun Suzuki's .
Thus in 1971, Nikkatsu's first roman poruno picture was Shogoro Nishimura's , 1971).
The story concerns an asexual husband whose wife eventually takes up a lover but a brothel's mamasan blackmails her into working for her.
These films featured whipping and torture, rape of repressed housewives, which continued into the 1990s with increasing intensity.