How many movies have Keiji Kubota and Masayoshi Yamaoka collaborated on?

They have worked on 3 movies together! Their first movie together was New Apartment Wife: Prostitution in Building #13 (1975) while their highest rated movie together was Oryu's Passion: Bondage Skin (1975). They have not worked together since Oryu's Passion: Bondage Skin (1975). They are most known for their drama films together.