How many movies have Koji Okumura and Shōji Sakai collaborated on?

They have worked on 7 movies together! Their first movie together was Chikan tsûkin-basu (1985) while their highest rated movie together was Subway Serial Rape: Office Lady Hunting (1986). They have not worked together since Subway Serial Rape: Lover Hunting (1988). They are most known for their drama films together.