Influenced by the straw-hat-wearing pirate Red-Haired Shanks, an enthusiastic young boy named Monkey D. Luffy dreams of one day becoming King of the Pirates.

While Alvida and her pirates plunder a cruise ship, they come across a barrel containing a strange boy named Monkey D. Luffy. The timid Koby befriends Luffy, and they share their grand dreams with each other.

In search of members for his pirate crew, Luffy and his new friend Koby arrive at Shells Town. There, they track down the renowned Pirate Hunter Zoro but run afoul of Helmeppo, son of the infamous Captain Morgan.

Luffy convinces the captive Zoro to join his pirate crew, but they must first defeat the tyrannical Captain Morgan.