How many movies have Yasumasa Koyama and Yoshihiro Sekiya collaborated on?

They have worked on 6 movies together! Their first movie together was The Anthem of the Heart (2015) while their highest rated movie together was Rascal Does Not Dream of a Dreaming Girl (2019). They have not worked together since Girls und Panzer das Finale: Part III (2021). They are most known for their animation films together.