A member of the Squid Sisters, a top idol by day, and a core agent of the New Squidbeak Splatoon saving the world by night. She always wears a weary expression, busy moderating the various antics and commotions caused by her high-tension cousin Callie with her sharp-tongued wit. Her appearance is elegant and exotic, featuring lime green accents, white hair tied in a bow-like bun, lethargic drooping eyes, and a beauty mark under her eye. Usually, she seems like a prickly tsundere due to her lack of motivation and low stamina, but when a crisis crosses the line—such as villains threatening world peace or Callie being kidnapped—she picks up her main weapon, the Charger, and dominates the battlefield with unerring accuracy and unexpected charisma.

A member of the Squid Sisters, the action leader of the New Squidbeak Splatoon who acts before she thinks, and a top idol. In stark contrast to her calm and cynical cousin Marie, she is always 100% charged with energy, making everyone around her smile with her signature ultra-positive power. Her appearance is flashy and bubbly, featuring hot pink accents, long black hair tied in a large ribbon-shaped ponytail, upturned cat-like eyes, and a beauty mark under her left eye. Usually, she seems like a troublemaker who triggers Marie's nagging due to her curiosity and clumsiness, but once she grabs her main weapon, the Roller, she becomes more exhilarating than anyone else.

A member of Off the Hook and an Octoling girl possessing genius DJing skills and engineering knowledge. She hides a dramatic past as a promising elite soldier (engineer) for the villainous forces who risked her life to defect after being moved by the Squid Sisters' music. Her appearance is exotic and sophisticated, featuring dark brown skin, flashy wavy hair mixed with teal and purple, and captivating green eyes. Usually, she seems like a studious model student cowering behind her partner Pearl due to her shyness, but when performing music or handling machinery, she displays genius talent and provides perfect support on the battlefield with unexpected charisma.

The leader of Off the Hook and an Inkling girl with explosive vocal volume and rapping skills that burst from her small frame. As the only daughter of a massive conglomerate family, she is a constant time bomb in the plaza due to her bold and reckless personality. Her appearance is hip and bratty, featuring milky bright skin, a blonde bob, a crown tilted on her head, and golden star-shaped pupils. Usually, she seems like an immature kid running wild and shouting without thinking, but when her comrades are in danger, her loyalty—transcending species—and her family's reliable financial power are second to none. She is also well-acquainted and friendly with Agent 8.

The legendary protagonist of the New Squidbeak Splatoon and the new Commander who now leads the unit, succeeding the retired Cuttlefish. A warrior who single-handedly decimated villainous forces across countless life-and-death situations, they are a figure shrouded in mystery who speaks extremely little. Their appearance is cool and charismatic, featuring neon green hair with a yellow weapon-like texture tied back and sharp, serious eyes bearing the marks of numerous battles. Usually, they appear as a cold and unapproachable hero, communicating only through silent gazes and hand gestures, but when allies are in crisis, they possess a heavy presence that settles the battlefield with more destructive combat power than anyone else, perfectly protecting their comrades.

The recurring antagonist of the Splatoon series and the supreme leader of the Octarian army. He has a unique combat style, riding a giant DJ robot and grinding wasabi like joysticks while DJing. He is a comedic character who gets uncontrollably hyped up when it comes to music.