The Summit War has thrown the entire world into chaos. Emboldened by Whitebeard's final words, pirates once again envision a wave they can ride into a new era. At Hancock’s order, Luffy is taken to Amazon Lily to hide from the Navy while he recovers.

Before they were brothers, Ace and Luffy lived in the mountains, dreaming of the day when they would take to the sea. In the criminal-infested junkyard known as Gray Terminal, Ace and his partner-in-crime Sabo robbed the thieves and scavengers.

Ace, Sabo, and Luffy made a promise to one another over cups of sake that would shape their futures. Yet while the brothers' adventures continue, Sabo's unfortunate past catches up with him. Meanwhile, a horrific plot unfolds.

Even as the fires in Gray Terminal threatened to consume them, Ace and Luffy fought Bluejam with all their might! In the wake of the tragedy, Sabo seized freedom in his hands and took to the sea, just as a Celestial Dragon arrived in High Town.

Luffy and Ace buried their sorrow and grew stronger day by day as they trained to be pirates. Time marched on, and they eventually bade farewell to their childhood home and took to the sea, hoping to achieve the dream that Sabo could not.

Determined to return to Sabaody and keep his promise to his crew, Luffy prepares for departure. However, when Dark King Rayleigh appears and makes him a surprising offer, Luffy is forced to make a decision that could alter the fate of his entire journey.

Although Navy HQ is in ruins after the Summit War, marines and reporters still stalk its grounds. Luffy, Rayleigh, and Jinbe return to where Ace died to carry out a mysterious plan. If all goes well, Luffy’s crew will understand his actions.

The Straw Hat Pirates have interpreted their captain's message to meet up again in two years. During this time, they will prepare themselves for the New World! In the Calm Belt, Luffy arrives in Luscaina to begin training under Rayleigh.