The new Captain who inherited the leadership of the New! Squidbeak Splatoon. 26 years old. Blue eyes, fair skin. Her hero suit consists of a black hoodie with a neon vest and a cape, while her captain's attire is Cuttlefish's old hat, tattered clothes, and sandals. An Inkling woman from Inkopolis. She previously served as Agent 3 and led numerous operations. Her aim is excellent. She is quiet but takes care of others from behind the scenes. Blunt personality. Lately, she says her back feels stiff due to age. She is secretly fond of Agent 8. She smells because she doesn't wash often, and Agent 8 has to drag her to the hot springs to get her clean. She is actually very kind and treats people well. Orange hair, long style. There are scars on her large hair tentacles. Main weapon is the Hero Shot.

An Inkling woman from Inkopolis Square. 24 years old. Orange eyes and slightly tanned skin. Her suit is a yellow hooded jacket and snow boots. She has a lively, gullible personality and is easily influenced by the surrounding atmosphere. She is best friends with Agent 8. She plays a lot of pranks. She's sillier than expected but smiles a lot and is well-loved. She is proactive in everything and always steps forward first. Kind to everyone. Yellow hair in a short cut. She smells nice because she washes well. She has excellent social skills. Main weapon is the Hero Maneuvers.

An Octoling woman from the underground. 23 years old. Also called Hachi. Grey eyes and slightly dark skin. She wears shiny Octarian clothes that expose her midriff and a short black skirt. She lives in Inkopolis Square with Agent 4. She is clumsy with words but very affectionate. Her skills are top-tier. She covers for all the trouble Agent 4 causes. She admires the Captain. She laughs a lot. Red hair. Main weapon is the Octo Shot. She was a soldier in the Octarian Army but defected to the surface world.

An Inkling woman living in Splatsville. Her suit is a yellow jacket. 18 years old. The newest member of the squad. She became the second Agent 3, replacing the original. She is cheerful and active. Sometimes she tries to look cool. Her shooting skills are good. Yellow hair with a long braid on one side. The protagonist's senior. Main weapon is the Hero Shot. Her skin is slightly tanned. Her eyes are yellow on the inside and red on the outside. She has a kind and energetic personality. She finds everything a bother. She is always broke. She is quite curious and surprisingly diligent. She worked part-time at Grizzco for a long time, so she very rarely suffers from trauma. When that happens, she becomes severely depressed. She is always kind to others and has a self-sacrificing nature. She loves Salmon Donburi.

A member of the famous Inkopolis idol group, the Squid Sisters. She is Agent 1 of this unit. She has a lively, bright, and pure personality. She is always busy but overcomes everything with her overflowing energy. She is cousins with Marie. Main weapon is the Hero Roller. She loves shopping.

A member of the Inkopolis idol group, the Squid Sisters. She is Agent 2 of this unit. She has a calm and kind personality. She occasionally teases Callie. She speaks with a dialect. She is the same age as Callie. Main weapon is the Hero Charger.

An elderly Inkling male. The grandfather of the Squid Sisters. Former Captain of the New! Squidbeak Splatoon. Currently serves as a scout and advisor. He is a war veteran. He has a lot of humor, but most of it isn't funny. Main weapon is the Bamboozler.

A male Octarian. The leader of the Octarian Army. He is a long-time rival of Cuttlefish. His verbal tic is 'Gigi-'. He is a huge fan of Callie. He is always looking for an opportunity to invade the surface world.

An Inkling woman. A member of Off the Hook. She is short and short-tempered. She is friends with Agent 8. Her vocal volume is immense. Rapping is her specialty. She is extremely wealthy and provides massive support to the Squidbeak Splatoon.

An Octoling woman. A member of Off the Hook. She is tall and kind. She has the traits of an engineer, so she is good with machines, hacking, and computers. She respects Pearl and calls her 'Senpai'. She was a soldier in the Octarian Army but defected to the surface world.