How many movies have Kazuki Yao and Yukihiko Nakao 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) and was their highest rated movie together. They have not worked together since One Piece "3D2Y": Overcome Ace's Death! Luffy's Vow to his Friends (2014).