How many movies have Katsuyoshi Nakatsuru and Takashi Muratani collaborated on?

They have worked on 4 movies together! Their first movie together was One Piece: Baron Omatsuri and the Secret Island (2005) while their highest rated movie together was Zatch Bell! Attack of Mechavulcan (2005). They have not worked together since Legend of the Millennium Dragon (2011). They are most known for their animation films together.