Many years ago, Woonan, a legendary pirate, plundered one-third of the world's gold and stashed it away on his secret island shrouded in mystery. In the present, Luffy and the rest of the Straw Hats continue on their journey to the Grand Line. They are robbed by a group of bandits. Led by their captain, El Drago, these same bandits are headed towards Woonan's famed island. Even though the Straw Hat Pirates must now recover their stolen treasure, they have gained another objective: to discover the lost island, its treasures, and learn about the legend of Woonan. There once was a pirate known as the Great Gold Pirate Woonan, who obtained almost 1/3 of the world's gold. Over the course of a few years, the pirate's existence faded, and a legend grew that he disappeared with his gold to a remote island, an island pirates continue to search for. Aboard the Going Merry, Luffy and his crew, starved and reckless, are robbed of their treasure. In an attempt to get it back, they wreck the getaway ship, guided by a young boy named Tabio, who's a captured part of El Drago's pirate crew. El Drago's love for gold has driven him to look for Woonan's island, and thanks to Woonan's treasure map, he finds it. During this time, Luffy's crew have been split up, and despite their own circumstances, they must find a way to stop El Drago from obtaining Woonan's gold.