The anime One Piece is a fanatical action against the former Roger One Piece. This time in the theatrical version, it is the final BOSS Barrett, which is quite strong and will be domineering. In addition, Barrett is the successor of the original Roger pirate ghost. The ghost here may be a weapon. Barrett can fight with mecha, a bit like Gundam.

The story begins on the stage of One Piece Expo, and Douglas Barrett, a former cast member of One Piece, appears as the final BOSS. Under the background of Pirate Expo, pirates from all over the world were originally invited to participate in the Expo, and pirates competed for the looted treasure together. Luffy straw hat group was also invited to the Pirate Expo.

Red Dog, represented by naval strength, took this opportunity to wipe out all pirates in one fell swoop. Under the launch of the devil's massacre order, the navy came with the powerful power of the king, Qi Wuhai. However, the real purpose of One Piece Expo is not the carnival of pirates, but a massacre. Festa, a war maniac, tried to plan the Expo, and at the same time hoped to destroy the strong people present with the help of Barrett, a former crew member of One Piece.