First person: I (soft, polite) Second person: you (friendly) / you (casual) Tone: Bright and energetic boyish tone. Honest and approachable. Appearance: A boy with reddish-brown hair wearing a bright pink hat. He has turquoise eyes, a round face, and wears a pale shirt with a red crossbody belt. He is the young son of Captain Colt and Betty's younger brother. He landed on the uninhabited Tomos Island with his companions and was left to watch the shore, but the pirate ship suddenly vanished, and his father and the others never returned. Since then, he has lived alone on the island. He meets Nobita, who washed ashore, calls him "Nobby," and becomes his friend as they travel together.

First person: I (tomboyish) Second person: you (blunt) / you (rough) Tone: Strong-willed, tomboyish, and big-sisterly. Appearance: A girl with red hair peeking out from a yellow hat. She features turquoise eyes and pink earrings, wearing a white shirt with an orange vest. Jack's older sister and a member of the Kidd Pirates. She is one of the few people who was genuinely moved by Gian's singing (which made Gian very happy to be praised sincerely; meanwhile, Jack was left speechless in shock). Her strong-willed and quick-to-fight personality and sensibilities match Gian's perfectly, to the point that she officially invited him to join the pirate crew when they parted.

First person: I (rough, masculine) Second person: you (blunt) / name without honorifics Tone: Bold and powerful pirate tone. Possesses the dignity of a captain. Appearance: A pirate-like man with tanned skin and long brown hair. Characterized by an eyepatch, a scar on his cheek, and a thick beard. He wears a black vest and a pendant with a large green ornament. The legendary pirate captain. He wears an eyepatch over his right eye. A muscular, dignified, and brave man who cares for his crew. He picked up a few of Doraemon's dropped Secret Gadgets, such as the Translation Gummy and the Dream Confirmation Machine. He is always calm and collected, serving as a reliable presence who barks orders to restore order when Doraemon and the others lose their cool. Without the Translation Gummy, Doraemon's group would likely have been a burden. He lands on the uninhabited Tomos Island, where treasure is said to sleep, to search for his suddenly missing brother, Captain Colt, and his crew.

First person: I (casual) Second person: you (blunt) / you (casual) / name without honorifics Tone: Bright and comical. Ends sentences with "-rez." Appearance: A tall man characterized by a pink hat, blonde hair, and a large mustache. Wears pirate attire. Kidd's subordinate. He has a lanky build. He gets separated from Doraemon and Kidd along with Pancho, but they disguise themselves in fishman suits to deceive the enemy and successfully help Doraemon and the others escape captivity.

First person: I (casual) Second person: you (blunt) / you (casual) / name without honorifics Tone: Friendly and down-to-earth. Comical way of speaking. Appearance: A short, round-faced man wearing a green bandana. Wears pirate attire. Kidd's subordinate. He works as a duo with Gonzalez. He has a short and stout build.

First person: I (rough, masculine) Second person: you (blunt) / name without honorifics Appearance: A powerful man with long brown hair and a large beard. He wears a red pirate-style jacket, a purple shirt, and a belt slung across his shoulder. Father of Betty and Jack. He fell into Cash's trap and was forced into labor along with his crew in the island's underground lake. After being rescued by Doraemon and the others, he cooperates to thwart Cash's ambitions. He is Kidd's older brother.

First person: I (soft, polite) Second person: you (friendly) / everyone Tone: Calm, kind, and gentle. Appearance: A dolphin with a vibrant pink and white body. Characterized by a big smile and black eyes, with a streamlined body and a long tail fin. A pink dolphin who is Jack's friend. He can communicate with humans via telepathy. His true identity is an officer of the Time Patrol, acting undercover to locate Cash's base. By looking at the map Nobita had, he was able to understand the rivers running through the island and discover Cash's base.

First person: I (formal, arrogant) Second person: you (polite) / you (blunt) / name without honorifics Tone: Haughty and cold. A composed tone that looks down on others. Appearance: A slender man with black spiky hair, a sharp nose, and a black goatee. He wears purple pirate clothes with yellow trim, red epaulets, and a green collar. However, the clothes he wears underneath are futuristic. A time criminal who came to the 17th century from the future. He built a secret base on Tomos Island and had Dr. Clone create modified creatures for pets or military use, which he sold for high prices as a merchant of death. (Creating modified creatures for unjust purposes is illegal; Cash claims there are no laws against it in the 17th century, but this is mere sophistry, which is why Ruffin of the Time Patrol was conducting an undercover investigation). His dream is to make a fortune by selling modified creatures to various eras. To gather labor, he scattered a large number of treasure maps to lure and capture pirates, forcing them into hard labor.

First person: I (old man style) Second person: you (polite) / you (blunt) Tone: Argumentative like a researcher. Becomes excitable when engrossed in experiments. Appearance: An elderly man characterized by grayish-purple hair and large round glasses. He has a thick beard of the same color and wears pale clothing, giving off a gentle yet energetic vibe. A scientist cooperating with Cash and one of the time criminals from the future. He is a mad scientist who creates new life forms through biotechnology; in the original story, it is mentioned he was expelled from the future's academic society because of this. He spent 30 years developing a creature modification device, creating legendary creatures like the Leviathan, Umibozu, Kraken, Grendel, and Bunyip, as well as various synthetic organisms.

Gender: Male Tone: Does not speak words; basically only roars and growls. The ultimate modified creature (biological weapon) created by Clone. It has a massive red dragon-like body, 263 meters in length. It operates underwater. Living up to its "ultimate" title, it possesses enough strength to destroy Captain Kidd's ship, the Sharg, with a single blow.