As a child, Monkey D. Luffy dreamed of becoming King of the Pirates. But his life changed when he accidentally gained the power to stretch like rubber...at the cost of never being able to swim again! Years, later, Luffy sets off in search of the "One Piece," said to be the greatest treasure in the world...

Camie the mermaid offers to take Luffy and the crew to Fish-Man Island if they'll help rescue her boss Hachi from the notorious Flying Fish Riders. Ignoring all of the warning signs (hint: her boss sounds suspiciously like an old enemy!), the crew agrees to help their mermaid friend, only to end up losing Camie to other kidnappers!