How many movies have Mai Kawana and Masahiro Kobayashi collaborated on?

They have worked on 4 movies together! Their first movie together was 赤い犯行 夢の後始末 (1997) while their highest rated movie together was Lascivious Nurse Uniform Diary: Two or Three Times, While I'm Wet (1997). They have not worked together since My Brother's Lover (1998).