How many movies have Takao Koyama and Toshio Furukawa collaborated on?

They have worked on 8 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: Broly – The Legendary Super Saiyan (1993). They have not worked together since Dragon Ball Z Side Story: Plan to Eradicate the Saiyans (1993). They are most known for their animation films together.