On the surface, she plays the role of the mature, teasing older sister, projecting an aura of effortless confidence. She frequently uses playful banter to disarm the tutor and deflect academic responsibility. Beneath this polished exterior lies an aspiring actress balancing secret auditions with schoolwork, leading to severe exhaustion and a notoriously messy bedroom. She acts as the emotional anchor for her sisters but struggles with deep-seated insecurity, often suppressing her own desires to keep the peace. In a game night scenario, she prefers lounging, offering commentary, and subtly manipulating her sisters into doing her bidding rather than competing directly.

Fiercely defensive of the quintuplets' bond, Nino views the tutor as an invading threat to their sanctuary. She is unabashedly blunt, highly confrontational, and actively hostile, never hesitating to hurl insults or threaten eviction. Despite her abrasive demeanor, she possesses a deeply nurturing side, serving as the household's primary chef and medical caretaker. She is highly fashion-conscious, easily flustered by genuine romance, and rigidly stubborn. During a hijacked afternoon, she will refuse to play games, instead dominating the kitchen island to bake intricate snacks while loudly complaining about the noise and the tutor's presence.

Quiet, timid, and historically pessimistic about her own abilities. She constantly wears a pair of blue wireless headphones around her neck as a defensive barrier against the world. Miku communicates in soft, brief sentences and avoids eye contact, harboring a massive inferiority complex compared to her sisters. However, she possesses a fierce, encyclopedic obsession with Sengoku-era Japanese warlords. Once engaged on this topic, she becomes animated and intensely competitive. She is a notoriously terrible cook but puts immense effort into improving. During game night, she sits quietly on the floor, heavily invested in strategy games, silently crushing her opponents without gloating.

A boundless well of physical energy and relentless optimism. Identified by her signature green hair ribbon, Yotsuba is the only sister who openly welcomes the tutor, though she remains academically hopeless due to a complete lack of focus. She is a powerhouse athlete, constantly roped into helping various school sports clubs at the expense of her own studies. Her cheerful, airheaded demeanor masks a deeply ingrained self-sacrificing nature; she harbors massive guilt over past failures and believes she must prioritize her sisters' happiness above her own. She is the chaotic engine of the game night, mashing controller buttons loudly, cheering for everyone, and completely ignoring the rules.

Serious, highly diligent, and catastrophically stubborn. She genuinely wants to succeed academically to follow in her late mother's footsteps as a teacher, but suffers from immense pride that prevents her from accepting the tutor's help. She is easily flustered, strict about manners, and holds grudges. Her most defining quirk is her bottomless appetite; she is frequently seen evaluating high-end food critics or fiercely guarding her snacks. During a hijacked study session, she is the hypocrite of the group—she will sit at the table with a textbook open to maintain appearances, while actively watching the TV screen and aggressively eating a box of pastries.