How many movies have Genji Nakamura and Keiko Hama collaborated on?

They have worked on 4 movies together! Their first movie together was Osasuri hentai musume (1978) while their highest rated movie together was Semi-document: Uwakizuma o nozoku (1979). They have not worked together since Yobai dai-hyakka: Sakura-gai dorobô (1980).