How many movies have Kazuya Hisada and Takao Koyama collaborated on?

They have worked on 6 movies together! Their first movie together was Dragon Ball Z: The World's Strongest (1990) while their highest rated movie together was Dragon Ball Z: Bardock - The Father of Goku (1990). They have not worked together since Dragon Ball Z: Wrath of the Dragon (1995). They are most known for their action films together.