Azusa was born into a musically-inclined family. Both of her parents were members of a jazz band, and Azusa began playing the guitar during her fourth grade in elementary school, eventually becoming quite good at it.
After finishing junior high, she was accepted into Sakuragaoka Girl's High School.
During her search, she stumbled across the Light Music Club several times, and together with her classmate Ui Hirasawa, visited the club's welcoming concert. Despite her previous misgivings about the Light Music Club, she was noticeably moved by their songs, which Ui had noticed, and decided to join the Light Music Club.
After enrolling at Sakuragaoka Girl's High School, Azusa Nakano, a freshman of said high school, is expressing her excitement to her new fellow classmates of her wish to join the school's Light Music Club, which Ui and Jun overhear.
Azusa hears that both Ui and Jun know the Light Music Club and when she ask them about it, she finds out that Ui's older sister is a member of the club. When Azusa learns from Ui that her older sister plays the guitar, she happily expresses her admiration for her for being the guitarist, revealing that she saw their performance during the school festival. Azuza continues to express her admiration for the entire Light Music Club and then excitedly asks Ui if the club itself is very popular and professional, which a very worried Ui can't give a proper answer to, thinking to herself how Azusa is overly glorifying her sister.
Sometime later, Azusa watches the Light Music Club's performance at the freshman reception ceremony. Later that day, she visits the clubroom to ask if she could join their club and is immediately, yet creepily, "secured" by the club's president, Ritsu Tainaka.