How many movies have Eiichi Kusumoto and Tadashi Iwata collaborated on?

They have worked on 6 movies together! Their first movie together was Gate of Hell (1953) while their highest rated movie together was Lone Wolf and Cub: Sword of Vengeance (1972). They have not worked together since Lone Wolf and Cub: Baby Cart in the Land of Demons (1973). They are most known for their drama films together.