How many movies have Kei Tsunematsu and Naoki Okabe collaborated on?

They have worked on 4 movies together! Their first movie together was Fate/stay night: Heaven's Feel I. Presage Flower (2017) while their highest rated movie together was Demon Slayer -Kimetsu no Yaiba- The Movie: Mugen Train (2020). They have not worked together since Demon Slayer -Kimetsu no Yaiba- The Movie: Mugen Train (2020). They are most known for their fantasy films together.