How many movies have Hachirō Kai and Nobumasa Mizunoo collaborated on?

They have worked on 17 movies together! Their first movie together was Sekkusu dokku: Midarana chiryō (1980) while their highest rated movie together was Nurse Diary: Beast Afternoon (1982). They have not worked together since Onsen Geisha: Yubune de Ippatsu (1982). They are most known for their drama films together.