How many movies have Kazuya Nakai and Kumi Nakajou collaborated on?

They have worked on 3 movies together! Their first movie together was One Piece: Giant Mecha Soldier of Karakuri Castle (2006) while their highest rated movie together was One Piece Film: Z (2012). They have not worked together since One Piece Film: GOLD (2016). They are most known for their adventure films together.