Azusa is a new student who joins the Light Music Club as a rhythm guitarist. She plays a Fender Mustang MG69/MH/CAR electric guitar which she eventually names Muttan, but is also in possession of a Gibson Les Paul Custom 50th Anniversary Gold Top (as seen in episode 13). She is a self-proclaimed novice guitarist who has been playing the guitar since the fourth grade and whose parents play in a jazz band. She is in the same year and class as Yui’s sister, Ui, and has quite a mysterious demeanor. She often finds herself bewildered by the tea parties and cosplaying aspects of the club when she would rather just practice, and is struck by how good the club’s music sounds despite their problems and lack of practice. However, she has a certain weakness for cakes and can be calmed down rather easily, sometimes by just being petted. She is more serious than the other girls, and does not like to admit how she really feels; she could be described in part as a tsundere. She is constantly hugged by Yui and is nicknamed Azu-nyan after trying on a pair of cat ears and meowing.
In the band, she looks up to Mio the most due to her maturity and the fact that she is an experienced musician, even trying to give Mio chocolate on Valentine’s Day. However, she sometimes unintentionally makes remarks concerning Mio’s weaknesses, such as her weight. She also finds Mugi very beautiful, and envies her hair and large eyes, and later starts teaching her how to play guitar when the two are alone in the club room. Since joining, Yui comes to her for advice on playing guitar, as well as maintenance. She gets a tan extremely easily, once during their time at the beach and another during a music festival (even after applying sunscreen). As a result, she frequently gets sunburned as well. She gets lonely very easily, and often worries that everyone in the club will leave her, as they are one-year-older and eventually will graduate. Due to this, the rest of the girls buy her a turtle to look after, naming it Ton-chan.
She is interested in a wide range of genres without limiting herself to anything in particular. She started playing instruments in fourth grade of elementary school, which makes it about 5 years of experience. Her parents both play in a jazz band.
Outside of the band, she often hangs out with Ui and Jun whenever the other girls are busy. When the others graduate, she becomes the new Light Music Club president alongside Ui and Jun, who decide to join her. Together with two new members, Sumire and Nao, they form a new band called Wakaba Girls. During the Wakaba Girls’ first summer training camp Azusa reveals to Sawako her belief that she is unable to act like a proper president for the Light Music Club; however, Sawako suggests that there is no proper way to define what it means to be a president and that Azusa will do just fine. While on that same training camp Azusa is convinced by the others to become the band’s vocalist despite her prior reservations on the issue, and eventually overcomes her weakness to sing in the school festival.
Her preference in clothing includes pants over skirts. Short pants are among the things she likes to wear. Her room is very tidy and not excessively cute.