How many movies have Kappei Yamaguchi and Masahiro Okamura collaborated on?

They have worked on 3 movies together! Their first movie together was Plastic Little: The Adventures of Captain Tita (1994) while their highest rated movie together was One Piece: Dead End Adventure (2003). They have not worked together since One Piece: Giant Mecha Soldier of Karakuri Castle (2006). They are most known for their adventure films together.