How many movies have Kappei Yamaguchi and Tomoaki Sakiyama collaborated on?

They have worked on 8 movies together! Their first movie together was Detective Conan: The Time Bombed Skyscraper (1997) while their highest rated movie together was Detective Conan: The Phantom of Baker Street (2002). They have not worked together since Detective Conan: Crossroad in the Ancient Capital (2003). They are most known for their animation films together.