How many movies have Kenichi Umemoto and Rikiya Koyama collaborated on?

They have worked on 4 movies together! Their first movie together was Detective Conan: The Darkest Nightmare (2016) while their highest rated movie together was Fate/kaleid liner Prisma☆Illya: Vow in the Snow (2017). They have not worked together since Detective Conan: The Scarlet Bullet (2021). They are most known for their action films together.