How many movies have Atsushi Nigorikawa and Rikiya Koyama collaborated on?

They have worked on 4 movies together! Their first movie together was Naruto Shippuden the Movie: The Lost Tower (2010) while their highest rated movie together was Detective Conan: Episode One - The Great Detective Turned Small (2017). They have not worked together since Case Closed: The Crimson Love Letter (2017). They are most known for their animation films together.