How many movies have Taketoshi Naitō and Tsutomu Nakamura collaborated on?

They have worked on 3 movies together! Their first movie together was The Betrayal (1966) while their highest rated movie together was Lone Wolf and Cub: Baby Cart in the Land of Demons (1973). They have not worked together since The Man Who Assassinated Ryoma (1987). They are most known for their drama films together.