How many movies have Mami Koyama and Rintaro collaborated on?

They have worked on 9 movies together! Their first movie together was Dr. Slump: Hoyoyo! Space Adventure (1982) while their highest rated movie together was The Tale of Osamu Tezuka: I'm Son-Goku (1989). They have not worked together since Yona Yona Penguin (2009). They are most known for their animation films together.