How many movies have Kappei Yamaguchi and Kenji Matsuoka collaborated on?

They have worked on 2 movies together! Their first movie together was One Piece: Episode of Chopper Plus: Bloom in the Winter, Miracle Cherry Blossom (2008) while their highest rated movie together was One Piece: Strong World (2009). They have not worked together since One Piece: Strong World (2009).