How many movies have Akira Kasahara and Hiroshi Masuoka collaborated on?

They have worked on 4 movies together! Their first movie together was Go! Anpanman: The Shining Star's Tear (1989) while their highest rated movie together was Go! Anpanman: Tears of the Mermaid Princess (2000). They have not worked together since Go! Anpanman: Tears of the Mermaid Princess (2000). They are most known for their animation films together.