Mahiru Tsuyuzaki is a second-year student in the Actor Training Department of Seisho Music Academy's 99th graduating class. Hailing from Hokkaido, she attended Kitachian Junior High School. Her passion for performance was ignited by her grandmother, who introduced her to singing, baton twirling, and stage plays, inspiring her application to Seisho to capture the confidence of admired actresses. Despite acceptance, the talent of her peers overwhelmed her, shaking her self-belief. Her training encompasses choir, piano, baton twirling, classical ballet, and modern dance, highlighted by a third-place finish in the 2016 Japan Baton Championship's U-15 solo twirl and runner-up in that year's National Junior High Baton Twirling Competition. Offstage, Mahiru appears withdrawn and thoughtful, a stark contrast to her passionate stage presence. She grapples with self-doubt and feelings of inferiority, often seeing herself as unremarkable. Her personality blends warmth, kindness, and a quiet determination to bring others joy, though she initially anchored her purpose solely in supporting her roommate, Karen Aijo. This reliance triggered intense jealousy when Karen reconnected with her childhood friend, Hikari Kagura, making Mahiru feel replaced and unnecessary. Her explicitly confirmed romantic feelings for Karen manifested as possessiveness and distress over Karen's shifting focus, culminating in her participation in the Revue of Jealousy where she confronted Karen directly. Physically, Mahiru possesses waist-length midnight-blue hair with blunt-cut bangs and slate-blue eyes, often styling two small sections to stick out like antennae. Her school uniform includes a gray blazer with dark gray trimming, a gray pleated skirt, a white button-up shirt, a red ribbon tie, brown loafers, and black crew socks. Casually, she wears a pale pink overall dress over a pale yellow shirt with trumpet sleeves and red canvas shoes. In the dorm, she favors a long pale yellow cardigan over a T-shirt with black leggings. For practice, she dons a black leotard with white leggings and a white crop top. Her revue costume features a green military-style jacket with gold piping, a white cravat, a green pleated skirt with a light green tulle tail, black boots with gold details, and a red pelisse jacket over one shoulder. Her weapon is a mace with an aquamarine gem, sometimes wielded like a baseball bat. Relationships drive Mahiru's growth. She deeply admires and feels a romantic attachment to Karen Aijo, viewing her as inspiration and stability. Hikari Kagura's arrival initially sparked rivalry; Mahiru resisted her moving into their dorm. After resolving her jealousy, Mahiru gradually accepted Hikari, eventually caring for her akin to Karen. She demonstrated enduring loyalty by helping Karen search for Hikari during her disappearance. Another key relationship is with Suzu Minase, a middle school acquaintance who intensely admired Mahiru's baton skills, training so hard she collapsed during joint practice. Their tense reunion during a cultural exchange program climaxed in the Revue of Summer Sky, where Suzu won, leading to their reconciliation. Mahiru's character arc centers on overcoming dependency and recognizing her intrinsic value. In the Revue of Jealousy, she challenged Karen over feelings of abandonment. Karen countered by affirming Mahiru's unique kindness and independent brilliance, helping Mahiru realize self-worth doesn't require validation through others. This breakthrough reignited her original motivation for attending Seisho: becoming a performer who brings audiences joy. Post-arc, she pursued her goals with greater self-assurance, aiming to join the New National First Theater Troupe and become a star capable of making everyone happy. Traces of her inferiority complex persist, but she now channels them into motivation. Additional details include her birthday (May 4), height (162 cm), and background as the eldest of six siblings from a Hokkaido farming family; she often shares home-sent produce. Her likes are baton twirling, watching baseball, and cleaning. Her dislikes are the card game Old Maid and sad stories. Her favorite food is potatoes; she avoids fava beans. Her name, Mahiru, homophones "midday" (真昼), and her surname, Tsuyuzaki, combines "dew" (露) and "cape" (崎). She is the franchise's only character with explicitly confirmed romantic feelings for another girl, consistent across anime, stage plays, and games. Her baton skills and love for baseball are directly inspired by her voice actress, Haruki Iwata.