How many movies have Harumi Okamoto and Ryusei Nishino collaborated on?

They have worked on 2 movies together! Their first movie together was Fullmetal Alchemist the Movie: The Sacred Star of Milos (2011) while their highest rated movie together was Maquia: When the Promised Flower Blooms (2018). They have not worked together since Maquia: When the Promised Flower Blooms (2018).