How many movies have Masataka Iwao and Tôru Nakajima collaborated on?

They have worked on 7 movies together! Their first movie together was New Battles Without Honor and Humanity 2: Head of the Boss (1975) while their highest rated movie together was Aftermath of Battles Without Honor and Humanity (1979). They have not worked together since Gate of Youth (1981). They are most known for their crime films together.