How many movies have Hiroshi Tachi and Yoshio Nakajima collaborated on?

They have worked on 5 movies together! Their first movie together was The Classroom of Terror (1976) while their highest rated movie together was Shinjuku's Number One Drunk-Killer Tetsu (1977). They have not worked together since Hell's Angels: Crimson Roar (1977). They are most known for their crime films together.