Luffy and his pirates can't wait to board the glittering Sin City ship known as Gran Tesoro, but they soon find themselves in way over their heads.

Set in Gran Tesoro, an independent country chartered by the World Government, home of the world's greatest entertainment city where well-known pirates, Marines, and millionaires throughout the world gather in an "absolute sanctuary" that even the World Government can't touch. There, the Straw Hat Pirates meet the ruler of the country, the golden emperor, Gild Tesoro, who easily wins pirates, the Marines, and even the World Government over to his side with money. He is about to take action to satisfy his bottomless ambition which may result in major changes in power relationships in the New World.