How many movies have Iku Ishiguro and Reiko Okuyama collaborated on?

They have worked on 3 movies together! Their first movie together was Hans Christian Andersen's The Little Mermaid (1975) while their highest rated movie together was Grave of the Fireflies (1988). They have not worked together since Grave of the Fireflies (1988). They are most known for their animation films together.