My comments only refer to the inclusion of scenes showing sexual activity openly in a mainstream genre film in Japanese cinema in 1970. I’ve re-edited the entry to make that clearer. As you suggest erotic material has been part of Japanese culture for centuries. However, in cinema the engagement with erotic imagery is quite complex and pinku eiga is seen as a distinct development in exploitation cinema linked to the decline of the studios from the late 1960s onwards. Elements of more open sexual imagery begin to move from experimental and art cinema into more mainstream cinema (where Nomura’s films were located) around 1970.