How many movies have Koki Uchiyama and Shunsuke Saitou collaborated on?

They have worked on 3 movies together! Their first movie together was The Anthem of the Heart (2015) while their highest rated movie together was How to Enjoy This World: Secret Story Film (2020). They have not worked together since Farewell, My Dear Cramer: First Touch (2021). They are most known for their animation films together.