How many movies have Ken Ootsuka and Yoko Soumi collaborated on?

They have worked on 3 movies together! Their first movie together was Anemone: Eureka Seven Hi-Evolution (2018) while their highest rated movie together was The Birth of Kitaro: Mystery of GeGeGe (2023). They have not worked together since The Birth of Kitaro: Mystery of GeGeGe (2023). They are most known for their animation films together.