How many movies have Sawako Yamamoto and Seiichi Nakatani collaborated on?

They have worked on 5 movies together! Their first movie together was Gundam Wing: The Endless Waltz (1998) and was their highest rated movie together. They have not worked together since Code Geass: Akito the Exiled 5: To Beloved Ones (2016). They are most known for their animation films together.