Post-War Arc

This twenty-third canon arc, also called the Post-Marineford Arc, closes both the Summit War Saga and the first half of the series. With the great war over, its waves spread across every sea, reshuffling the Warlords, the Marine command, and the pirate landscape. At its heart sits a long flashback to Luffy's boyhood on Dawn Island alongside his brothers Ace and Sabo, framing a personal story of grief and recovery that culminates in the crew's decision to separate and train for two years.

In the aftermath, the world cheers the Marines' victory while new crews surge onto the seas and pirates lose Whitebeard's protection. Hancock and Law carry the critically wounded Luffy to Amazon Lily, where he wakes in a frenzy of denial before Jinbe finally confirms Ace's death, breaking him completely. A sweeping flashback then recounts how young Luffy was placed with the mountain bandit Dadan, met the hostile Ace, and earned his trust by refusing to betray him under torture by the Bluejam Pirates. The three boys, joined by the runaway noble Sabo, swear brotherhood over sake. Their bond is shattered when nobles burn down the Gray Terminal and a passing Celestial Dragon shoots down Sabo's small boat, presumably killing him. Ace and Luffy vow to grow strong and become pirates, eventually setting sail years apart.

Returning to the present, Jinbe pins Luffy down and helps him realize he still has a loyal crew waiting, and Luffy resolves to return to them. Rayleigh arrives on the island with a plan. Meanwhile, scattered across the world, each Straw Hat independently learns of Ace's death and Luffy's plight through the newspapers and rushes to reach their captain. In a bold message, Luffy, Jinbe, and Rayleigh slip back into Marineford, ring the Ox Bell sixteen times, and lay flowers at the battle site, an act the Marines read as a declaration of war. The signal is actually meant for his crew. On Rusukaina near Amazon Lily, Rayleigh begins training Luffy in the three forms of Haki, while a tattooed message reading 3D2Y reveals the new plan: rather than meet in three days, the crew will reunite in two years, each having trained alone.

The arc reorders the post-war world and launches the timeskip. Sengoku and Garp resign their posts, Sengoku recommends Aokiji as the next Fleet Admiral, and Smoker transfers to the New World's G-5 base hoping to chase Luffy. Doflamingo finishes off Moria on the government's orders, and the freed Level 6 prisoners scatter as the World Government hides the breakout. The Sabo flashback quietly preserves a brother the audience believes dead, a thread revived much later, while Koby's newly awakened Observation Haki and the crew's individual training journeys all set up the two-year leap. By the arc's end, Luffy has placed his straw hat on a rock and begun the training that prepares the Straw Hats to enter the New World.