How many movies have Kappei Yamaguchi and Ken Ootsuka collaborated on?

They have worked on 7 movies together! Their first movie together was Case Closed: 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 One Piece Film: Strong World (2009). They are most known for their animation films together.