How many movies have Hideko Okimoto and Joji Yanami collaborated on?

They have worked on 7 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: The History of Trunks (1993). They have not worked together since Dragon Ball Z: Broly – The Legendary Super Saiyan (1993). They are most known for their science fiction films together.