Portgas D. Ace

Ace was much more intelligent, polite, and generally, more bearable than Luffy, which prompted the Straw Hat Pirates to question whether he was truly related to their captain. While several people who knew Gol D. Roger noted Luffy is quite similar to the late Pirate King, Whitebeard himself claimed that Ace's personality was not at all like his father's. It seems that among the very few things the brothers shared was their recklessness as pirates. In addition, Ace liked to party as much as his brother does. When he boarded Buggy's ship, he was drawn by the smell of food and decided to enjoy himself while he was there. Ace could be a bit inappropriate though as he once used a woman's skirt to wipe his face while he was dining at Spice Bean in Arabasta.

There were two running gags about Ace. The first was his rather extreme narcolepsy. He tended to randomly fall asleep while eating and conversing, leaving strangers around him wondering if he had died. This was first seen in Arabasta when they thought he died in the middle of eating. The second was that he did a "dine and dash" routine wherever he went. This went back to his younger days with Sabo and Luffy, when they would often dine and dash in the city of Goa, and carried over to adulthood, as shown on three occasions when he was on Drum Island, Arabasta, and Lulusia Kingdom.

Ace was also shown to be quite impulsive, much like his younger brother, as he too would make hasty decisions and, in some cases, neglect listening to reason.

His "politeness" is due to Makino's teaching after Ace asked her how to introduce himself to Shanks. Before that, Ace was rather cold and rude to anyone he was not familiar with.

As the son of Roger, he lived in his shadow and is to date the first D. depicted to truly question his own right to exist, while displaying the fewest commonly seen D. related traits. Ace seemed to have lifelong problems dealing with his parentage, even after denouncing Gol D. Roger and accepting Whitebeard as his only father. Ace believed that it was natural if he were to really die as nobody in the world wanted the son of the devil to live.

Benn Beckman of the Red Hair Pirates described Ace's personality to be naiver than his appearance would suggest. Ace is described to be more of a fighter than a Pirate.

Ace had a tendency to never back down from a fight, saying that he would never run once facing an enemy. Also like his father and brother, Ace was confident and fearless when confronting his opponents even when they were extremely powerful people such as Whitebeard or admirals, though like Luffy, he could also underestimate his opponents. He also tried to kill Whitebeard at least a hundred times despite the massive difference in strength between them and each of his attempts failing miserably. Because of this, some people believed that Ace had a death wish, but in truth, he wanted to prevent the people he cared for from getting hurt. While Ace emerged victorious over enemies he refused to run from, his stubbornness hurt him on a number of occasions.

Ace was also easily provoked by and became violent towards anyone who insulted or harmed people close to him. In one of Garp's conversations with Curly Dadan, this was revealed to be a trait of Roger as well. During his childhood, Ace had a tendency to severely injure anyone who insulted Roger, though he himself disliked his biological father. After hearing about Sabo's presumed death at the hands of a World Noble, Ace quickly became bent on killing the Noble and Dadan had to pin Ace down and tie him to a tree to stop him.

Ace's temper got the better of him, especially in cases when Whitebeard, proclaimed by Ace to be his only father, was insulted.

Although Ace follows the creed of loyalty towards those close to him, he was not above using underhanded methods to win a fight at times.

Alongside his loyalty is Ace does not judge people by their appearance and race, but by their character.