How many movies have Ikunosuke Koizumi and Mitsuyoshi Hikawa collaborated on?

They have worked on 7 movies together! Their first movie together was Enka Jôshikô: Kizudarake no Kaben (1973) while their highest rated movie together was A Woman Called Sada Abe (1975). They have not worked together since International Stewardess: Erotic Flight (1976).