How many movies have Kazuya Nakai and Shigenori Taniguchi collaborated on?

They have worked on 2 movies together! Their first movie together was One Piece: Chopper's Kingdom on the Island of Strange Animals (2002) while their highest rated movie together was One Piece: Giant Mecha Soldier of Karakuri Castle (2006). They have not worked together since One Piece: Giant Mecha Soldier of Karakuri Castle (2006).