Azusa Nakano enters Sakuragaoka High School as a disciplined first-year drawn into the Light Music Club by a school festival performance, only to find its members favoring tea breaks over practice. Her rigorous musical upbringing—shaped by her jazz musician parents and years of guitar training since elementary school—clashes with the club’s carefree habits. Armed with her cherished Fender Mustang "Muttan" and a later-acquired Gibson Les Paul for home use, she oscillates between frustration and reluctant adaptation, becoming the group’s pragmatic anchor who nudges them toward rehearsals while secretly softening at the lure of sweets or affectionate teasing.

Her initial resolve to quit falters as bonds deepen, particularly with airheaded guitarist Yui Hirasawa, who dubs her "Azu-nyan" after coaxing her into cat ears during a performance. The nickname sticks, mirroring her gradual embrace of the club’s quirky warmth. Beneath her tsundere exterior—masking care with curt remarks—lies a fear of solitude that erupts when faced with her seniors’ impending graduation, culminating in a raw, tearful appeal for them to stay. Post-graduation, she shoulders leadership as club president, mentoring newcomers while battling self-doubt under advisor Sawako’s guidance. Reluctantly stepping into the vocalist role for the Wakaba Girls, she pushes past insecurities to honor the group’s legacy.

Standing 150 cm with black pigtails and a propensity for sunburns, her meticulous nature surfaces in planning the London graduation trip and tutoring Yui, yet sun-tan mishaps humorously undercut her poise. The seniors’ farewell gift, the song "Tenshi ni Fureta yo," echoes her emotional core, bridging her growth from a strict perfectionist to a leader who melds discipline with the Light Music Club’s joyful chaos. Her journey weaves vulnerability and resolve, preserving the club’s spirit while carving her own path.