A man is trapped on the East Blue islandSixis, with the irregular current around it preventing him from escaping; he desires to write an adventure essay. He encountersPortgas D. Ace, and thinks the young pirate has come to rescue him, but Ace has actually been shipwrecked on Sixis as well for twice as long as the man. Ace offers for the two of them to build a raft together, and they find out they are searching for the same treasure on the island. Ace asks the man his name, and he is reluctant to give it because he cast it aside when he went out to sea. He tries to use Ace as his pen name, but Ace suggests the similar-sounding name Deuce. The man accepts it, and Ace decides to call himMasked Deuce because of the mask the man wears.
Masked Deuce tells Ace that he was a medical student with bad grades, and his parents were indifferent to him; he wants to go out to sea just so he can enjoy an adventure. Ace talks about his family as well, specifically Luffy, but during their conversation Deuce ends up mentioning that someone who was the offspring of Gol D. Roger would probably not be too happy, causing Ace to become sullen. Deuce realizes that Ace must be Roger's son, and with conflicting feelings, he departs from Ace and tells him not to talk to him anymore.
Several days pass, and Ace continues to be unsuccessful in escaping from Sixis, while Deuce cannot find any food or water. He sees Ace holding a fruit on the beach, and decides to kill him for the fruit. However, before he can attack with a tree branch, his stomach growls. Ace notices him and thinks he has come back to help build a raft, offering him his fruit. Deuce feels guilty about his intended actions and refuses the fruit, but when he reconciles his differences with Ace, the two decide to share it. It tastes terrible, but Deuce discovers that Ace's body is on fire afterwards; they realize that the fruit they ate is the Mera Mera no Mi. Several days later, Ace has learned to control his fire and the duo has built a ship called the Striker, which runs on Ace's firepower. Deuce reveals that there actually is no treasure hidden on this island, but the newly empowered Ace is not so sure. Ace offers for Deuce to come with him, and Deuce agrees, saying he can write an adventure essay now. The two shake hands, forming the Spade Pirates, with Ace declaring that he wants to go beyond Pirate King.
