Nami betrays the Straw Hat crew and steals their ship and treasures, escaping to Arlong Park. Luffy and his crew follow her, only to come face to face with the infamous pirate Arlong, a ruthless fish-man who has taken over Nami's home island with force and Naval bribes. As opinions clash and the Straw Hats attempt to convince Nami to rejoin the team, her true motivation behind the deception will be revealed at last.

After Brook questions the origin of the Mini Merry name, Usopp and Chopper Tony Tony recall the adventures of the Straw Hat Crew's beloved ship, friend, and crew member—the Going Merry. Ussop abandons the crew for a fight over the Going Merry while Robin Nico leaves with the government's top assassin group, CP9. In order to bring the crew back together, Monkey D. Luffy and the remaining Straw Hats follow Robin to rescue her from the claws of the World Government.

The special will revisit the childhood past of the three sworn brothers Luffy, Ace, and Sabo, when they all dreamed of becoming pirates. In addition, it will depict how Sabo originally came into the kingdom of Dressrosa (which was not depicted in Eiichiro Oda's original manga or the television anime), as well as his reunion with Luffy from his point of view.

Meet the Osomatsu boys—sextuplets who look, speak, dress and talk like the same. They only add to the hyper eccentric residents of the town who easily break any boundaries defined by common sense. Check your logical thinking and reason at the door and immerse yourself in everyday lives of unique characters who are wild both in appearance and temperament! (Source: Studio Pierrot)