Satowa Hōzuki is a first-year koto prodigy at Tokise High School, standing 158 cm tall as the smallest koto club member. She has long dark hair—often worn down or in a ponytail—brown eyes, and distinctive features. Her standard wardrobe includes Tokise High’s winter uniform (white blouse, red-orange striped bow tie, checkered brown skirt, blue socks, brown shoes, blue blazer) or the summer variant with a blue blouse without the blazer.

Heir to the prestigious Hōzuki School, her privileged childhood unraveled after her father Reiji’s death. Her mother Chiharu, overwhelmed by the school’s legacy, grew abusive, culminating in Satowa’s exile when she defied traditional playing styles during a national competition. Determined to prove herself alone, she initially pursued solo koto victories but recognized the necessity of collaboration.

Initially aloof and critical—dismissing clubmate Chika Kudō as "ridiculous and dumb"—Satowa softened through the Tokise Koto Club’s influence. She joined intending to elevate her reputation by transforming the obscure club into national contenders. Her focus shifted to collective growth as she taught novice members, though articulating techniques proved challenging due to her innate skill. Her absolute dedication to koto earned her the "koto-baka" (koto-obsessed) moniker, often neglecting other abilities.

Relationships evolved profoundly: friction with Chika turned to mutual respect after learning his troubled past, blossoming into romantic feelings. She openly confessed while shielding him in a fight, and their bond deepened when he protected her from a falling koto, injuring his wrist pre-performance. Kazusa Ōtori of Himesaka Girls’ Academy persistently sought to recruit her, reflecting Satowa’s renown. Club advisor Suzuka Takinami and mentor Akira Dōjima guided her growth, with Dōjima aiding her teaching hurdles.

Reconciling her past became pivotal. Estranged from her mother and the Hōzuki School, Satowa reconnected through music. Her national preliminaries performance moved Chiharu, reinstating her as heir. This resolution marked her journey from isolation to acceptance, showcasing koto as an expression of shared humanity over technical perfection. The club’s "All Your Powers Combined" ensemble highlighted her shift from solo ambition to valuing collective harmony.

Her surname Hōzuki merges "phoenix" (鳳) and "moon" (月), evoking rebirth and clarity. She enjoys monja (savory pancakes), dislikes cold rice, and tactically adopts a "damsel in distress" persona to manipulate situations before resuming her direct demeanor.