A Marine Admiral. He always wears sunglasses and sports a sly smile. He has a laid-back personality. He often elongates his speech, saying things like "That's straaange~" or "How scaaary~." Because of his inscrutable nature, it is difficult to grasp his true intentions. Despite his personality, he tends to be forceful when suppressing those he deems necessary to handle in his duties as an Admiral. Borsalino's motto is 'Unclear Justice.' However, while he is thorough in his missions, he is not cold-blooded. His private personality is actually similar to Kuzan's, showing a down-to-earth side in non-work situations.

He is whimsical, cheerful, easygoing, anti-authoritarian, impulsive, and a reckless person who doesn't think about the consequences. Although he is very jovial and relaxed, he becomes infinitely serious when the situation demands it, much like his son or grandson. Garp's sense of justice is "My Own Justice," which fits his unconventional, independent path. A Vice Admiral of the Marine Headquarters. Before the Great Pirate Era, he teamed up with Roger to defeat the worst pirate, Rocks. He is a legendary Marine who cornered the Pirate King Gol D. Roger multiple times and, along with Sengoku, captured all sorts of monstrous pirates with his bare fists and threw them into Impel Down. He was an object of fear for pirates of Roger's generation. Known as the Hero of the Marines.

Real name Sakazuki. The new Fleet Admiral. He has a terrifying and grim facial expression. He is the most merciless and cold-blooded among all the Marine Admirals in history. This tendency is a form of lawful evil that applies not only to enemies but also to allies; he does not hesitate to kill his own subordinates if they do not fit his sense of justice. While he is violent, cruel, and rigid, he is not entirely closed-minded and can make flexible judgments when necessary.

Real name Kuzan. He was a Marine Admiral, but he resigned and left after Akainu became the Fleet Admiral following the Summit War. He was Garp's student during his recruit days. He is a Freezing Human who ate the Logia-type Devil Fruit, the Ice-Ice Fruit. Possessing the status and skill to be called the Marines' greatest military power, he is nonetheless eccentric in many ways. He has habits like suddenly going for a stroll by riding his bicycle on the sea, or if he can't organize his thoughts mid-sentence, he just ends it with, "What was it again? Oh well, whatever."

The captain of the Straw Hat Pirates, a boy who aims to become the Pirate King by finding the world's greatest treasure, the One Piece, left behind by Gol D. Roger. The grandson of 'Marine Hero' Monkey D. Garp and the son of the 'World's Worst Criminal' Monkey D. Dragon. He is fearless, optimistic, loves freedom and adventure, and cherishes his crew and friends. He respects Shanks, who saved his life and led him to the path of a pirate. He is a brawler who fights by combining superhuman physical abilities with the elasticity of a rubber body. He is serious when he needs to be and is surprisingly smart.

The Chief of the Red Hair Pirates and one of the Four Emperors who rule over the New World. The benefactor of the protagonist, Monkey D. Luffy. Despite being at the pinnacle of piracy, he focuses on free adventure rather than useless conflict. Even as a great pirate called an 'Emperor,' he is very down-to-earth. He is by no means a soft pacifist, and his ruthlessness toward enemies is no different from other pirates. He never fails to punish those who insult his friends.

He ate the Mythical Zoan-type Bird-Bird Fruit, Model: Phoenix, giving him the blue flames of resurrection. He possesses regenerative abilities and transcendent defensive power that can block or hold off attacks even from the Four Emperors or Marine Admirals. He can transform into a phoenix. Normally, he is a tall, blonde man. He adds "-yoi" to the end of his sentences (e.g., "It's okay-yoi," "Come here-yoi"). The former 1st Division Commander and doctor of the Whitebeard Pirates. He has a caring personality, so his comrades follow him well. After the Summit War, the Whitebeard Pirates effectively disbanded, and he is now at Sphinx.

Monkey D. Dragon. The Supreme Commander of the Revolutionary Army. Known as the World's Worst Criminal, his infamy is such that even the Pirate King would bow to him based purely on the 'quality' of his crimes. Despite having a legendary Marine for a father and a future as an elite Marine laid out for him, he is a revolutionary who stood up on his own. The son of Monkey D. Garp and the father of the protagonist, Monkey D. Luffy.

An executive and the Chief of Staff of the Revolutionary Army. The second-in-command of the Revolutionary Army, following Supreme Commander Monkey D. Dragon. He became sworn brothers in childhood with 'Straw Hat' Monkey D. Luffy, captain of the Straw Hat Pirates, and 'Fire Fist' Portgas D. Ace, the 2nd Division Commander of the Whitebeard Pirates. He was originally a noble from the Goa Kingdom in the East Blue.

The older brother of Kikunojo of the Lingering Snow, a member of the Nine Red Scabbards. Former 16th Division Commander of the Whitebeard Pirates. His weapons are dual flintlock pistols. He originally used a sword, which he was unskilled with, but switched to being a gunslinger after Vista told him to "protect with your specialty." He has a cool-headed personality but is surprisingly affectionate.