Ace is much more intelligent, polite, and generally, more bearable than Luffy, which prompts the Straw Hat Pirates to question whether he is truly related to their captain. He has rather extreme narcolepsy and randomly falls asleep while eating and talking, leaving strangers around him wondering if he has died. He has a tendency to never back down from a fight, saying that he would never run once facing an enemy. Despite this, he's a very kind person and hates seeing friends hurt or crying.