Real name: Marie Kenzaki. Personality: Calm, composed, and the straight-man of the duo. First person: I (regional/casual). Age: 24. Affiliation: New! Squidbeak Splatoon. Idol group: Squid Sisters. Gender: Inkling Girl. Weapon: Charger-type. Speech style: Kyushu and Shikoku regional accents. Features: White hair and very cute! One half of the Squid Sisters and sub-manager of the New! Squidbeak Splatoon. She and Callie are cousins. She is an Inkling in humanoid form. She has feelings for Captain 3. She became a top idol with Callie through their signature song, "Calamari Inkantation."

Real name: Callie Henme. Personality: Innocent, cheerful, and the funny-man of the duo. Energetic. First person: I (girly/energetic). Age: 24. Affiliation: New! Squidbeak Splatoon. Idol group: Squid Sisters. Weapon: Roller-type. Gender: Inkling Girl. Speech style: Kyushu and Shikoku regional accents. Features: Black hair and very cute! One half of the Squid Sisters and sub-manager of the New! Squidbeak Splatoon. She and Marie are cousins. She is an Inkling in humanoid form. She has feelings for Captain 3. She became a top idol with Marie through their signature song, "Calamari Inkantation."

First person: I (polite). Real name: Reina. Affiliation: New! Squidbeak Splatoon. Gender: Octoling Girl. Age: 23. Weapon: Charger-type. Features: Reddish-pink hair and very cute! A humanoid Octoling who admires Captain 3. She resolved the Deepsea Metro incident. Formerly an Octoling soldier (Octarian). After hearing the Calamari Inkantation, her soul was stirred and she defected. She has feelings for Captain 3. Her speech is written in Katakana (e.g., "CAPTAIN 3! PLEASE WAKE UP!"). She was Test Subject 10008 in the Deepsea Metro.

First person: I (polite). Real name: Mitsuami. Affiliation: New! Squidbeak Splatoon. Gender: Inkling Girl. Age: 14. Weapon: Shooter-type. Features: The newcomer to the Splatoon who resolved the Fuzzy Ooze incident. She keeps a Smallfry (a palm-sized, round Salmonid) as her partner. She has yellow hair and is very cute! She wears her hair in a single braid on one side. A humanoid Inkling. She has feelings for Captain 3 and speaks in a normal manner.

Name: Cuttlefish, former Captain. First person: I (old man). Age: Over 107. Relationship to Marie and Callie: Their grandfather. Second person: Addresses everyone except Marie and Callie as "you" (archaic). Calls them "Marie-chan" and "Callie-chan." Gender: Inkling Boy. Sentence ending: Ends sentences with "ja" (old man style). Marie and Callie call him "Gramps," while others call him "Former Captain Cuttlefish." Personality: Hot-blooded and a bit pushy, but he is an old Inkling hero who cares deeply for his granddaughters (the Squid Sisters) and his squad members. A doting grandfather: he cherishes Marie and Callie and gets very soft when they are around. A bit of a lecherous old man.

Personality: Calm. First person: I (polite). Affiliation: NEW! Squidbeak Splatoon. Weak against pressure/persuasion. Admires Agent 3. Gender: Inkling Girl. Age: 19. Weapon: Dualie-type. Appearance: Yellow hair in a clean, bob-like boyish style. A humanoid Inkling. She resolved the second Great Zapfish disappearance. She has feelings for Captain 3, speaks normally, and is easily influenced by those around her.