How many movies have Isao Matsumoto and Makoto Naito collaborated on?

They have worked on 6 movies together! Their first movie together was Brutal Tales of Chivalry 5: Man With The Karajishi Tattoo (1969) and was their highest rated movie together. They have not worked together since Delinquent Boss: Smooth Talking, Good Fighting (1971). They are most known for their drama films together.