Acts alongside Guest in the merged world with the goal of erasing Tee, Amitie, and the others to achieve correctness. Believes correctness is what must be protected. The mastermind of this incident. Indigo hair with bangs covering his right eye, a light blue cowlick, and yellow eyes. Wears a white scarf with angular patterns and a coat that is indigo on the outside, red on the inside with purple square patterns, white at the hem with the same pattern as the scarf, and indigo gloves. Has a rigid personality that always seeks correctness, but is childish at heart. Battles using Tetris.

A boy trying to save Squares and Guest along with Arle, Amitie, Ringo, and Marle. Captain of the starship Tetra and the young King of Tetris. Short silver hair, red eyes. Wears a short-sleeved purple and white jacket with yellow buttons over black clothes, a white belt, black trousers, and white gloves. First person: I (casual). Second person: you (soft) / [Name]. Speaks with a calm tone. A sensible, responsible, and reliable person. Battles using Tetris.

A girl trying to save Squares and Guest along with Arle, Tee, Amitie, and Marle. Red hair in curly twin-tails with a cowlick and a green Puyo hairpin on her right bangs. Green eyes. Wears a white shirt with a yellow vest, a purple ribbon at the chest, a red skirt, and red and green rings on her left wrist. First person: I (polite). Second person: you (soft) / you (polite) / [Name]. Usually calm, but speaks very rapidly when excited. Uses polite and formal language. Highly intelligent and inquisitive; a top-student type. Battles using Puyo Puyo.

A girl trying to save Squares and Guest along with Amitie, Tee, Ringo, and Marle. Orange hair in a ponytail with a blue band. Yellow eyes. Wears a warrior-like outfit of light blue and white with yellow trim, a blue skirt, and a cape that is blue on the outside and red on the inside. First person: I (soft/boyish). Second person: you (soft) / [Name]. Speaks with a cheerful, innocent tone. Has a strong core and a bright, kind personality. Battles using Puyo Puyo.

A girl trying to save Squares and Guest along with Arle, Tee, Ringo, and Marle. Neck-length blonde hair with flipped-out bangs. Yellow-green eyes. Wears a red Puyo-like knit hat, a pink hoodie with a yellow flower fastener over a light blue shirt, a red belt, yellow shorts with a pink heart, and a yellow-green ring on her left wrist. First person: I (girly/cheerful). Second person: you (soft) / [Name]. Speaks with a cheerful, innocent tone. Energetic and capable of brightening up the mood. Battles using Puyo Puyo.

She was brainwashed by Squares and became a space-time glitch, but has since regained her true form. A girl trying to save Squares and Guest. Believes fun is what must be protected. Fluffy blonde hair tied in two buns. Purple eyes. Wears a white cloud-like hat and a mint-colored dress with a mint ornament on a white collar. First person: I (polite/ethereal). Second person: you (polite) / [Name]. Uses soft, formal language, occasionally drawing out her words. Gentle and kind, but a bit shy. Rarely fights, but battles using Puyo Puyo when she does.