Monkey D. Luffy is a young man determined to become King of the Pirates. After a series of unexplained incidents he ends up sleeping inside a barrel which ends up being rescued by a passenger ship. The evil pirate Alvida invades the ship with her crew, including an enslaved boy named Koby. Luffy meets Koby and convinces him to fight for his own dream, no matter the consequences. Luffy takes to battle the crew using his Gomu Gomu powers, which he gained after eating a Devil Fruit, the Gomu Gomu Fruit (Gum-Gum Fruit). After beating Alvida with one Gomu Gomu Pistol, Luffy and Koby set sail to find the Pirate Hunter Roronoa Zoro.
Aboard a passenger ship 2 sailors spot a barrel floating. The ship is hosting a formal dance for the rich passengers, among them a pretty young girl is invited to dance. Back outside the sailors try to reel the barrel and succeed in when another sailor spots a Pirate ship approaching.
The pirate ship attacks with cannons, creating panic among the passengers. Among the commotion the barrel rolls into the kitchen while the pretty young girl runs outside to see the attackers. The Pirates board the ship, all except for the weak Koby. Alvida kicks Koby aboard the attacked ship after charging in herself.