How many movies have Hachirō Kai and Miki Yamaji collaborated on?

They have worked on 6 movies together! Their first movie together was Office Lady Rope Slave (1981) while their highest rated movie together was Nurse Diary: Beast Afternoon (1982). They have not worked together since Horny Working Girl: From 5 to 9 (1982). They are most known for their drama films together.