The story opens on Pirate Zap's ship, where two of his crew, Bonney and Maccus, are tired and want to escape, but unfortunately they have no money. Three children, Amanda, Milia and Holy, who are being held captive on the ship overhear them. Amanda, who's father was a pro treasure hunter, knows the whereabouts of a great treasure, and offers them a deal. They agree, and the five of them barely escape and make it onto a small island where they meet Luffy and his crew. Unfortunately, they were pursued and Luffy and Amanda are captured and brought back to their boss, the head of the Bayan Pirates, who is also after the treasure. Now Luffy and the others must battle the Bayan Pirates and find the treasure that Amanda's father had left for his children.