Alisa Ayase is the younger sister of Eli Ayase. She initially attends middle school before enrolling as a first-year student at Otonokizaka High School, later becoming a third-year student by the end of the film’s timeline. Having spent a significant period living in Russia with her grandmother, she is initially unfamiliar with some Japanese customs, once mistaking a canned oden snack for a typical beverage. She has light blonde hair, blue-green eyes, and is often seen with a snowflake-shaped hairpin on the right side of her head. Alisa is gentle, shy, understanding, and earnest, presenting a more reserved and softer contrast to her older sister’s more assertive nature. She is a devoted and enthusiastic fan of the school idol group μ's, demonstrating deep admiration for its members and activities. This passion is evident in her emotional reactions, such as her visible excitement when meeting Umi Sonoda and her disappointment when she believes Umi does not recognize her. She is also forthright in her opinions, notably telling Eli that she disliked a speech she had given and questioning whether it truly reflected what Eli wanted to do. Alisa shares a verbal tic with her sister, the Russian exclamation "Khorosho!" (Хорошо!), which she pronounces with a more authentic rolled 'r' sound. Her initial role in the story is as a catalyst regarding her sister’s involvement with μ's: when Umi Sonoda discovers her listening to an unreleased live performance recording, Alisa explains that Eli recorded it for her, indirectly revealing Eli’s secret interest. As the story progresses, Alisa becomes a committed supporter, attending live performances and expressing her desire to one day join the group when she enters high school. She forms a close friendship with Honoka Kosaka’s younger sister, Yukiho Kosaka, who is her classmate and shares her interest in school idols. Among all μ's members, Alisa holds a particular admiration for Umi Sonoda. After successfully enrolling in Otonokizaka High School, she eagerly looks forward to joining μ's. However, as the third-year members, including Eli, approach graduation, Alisa comes to realize that μ's is a unique and irreplaceable group comprised solely of its original nine members. She decides to give up her personal ambition to join them, sharing this decision with Honoka and helping solidify the remaining members’ resolution to end μ's activities after the third years graduate. Instead of being discouraged, Alisa and Yukiho resolve to form a new idol unit to carry on the spirit of school idols at Otonokizaka. By the film’s conclusion, both are seen as third-year students and active members of the school’s Idol Research Club, where they introduce the legacy of μ's to new students. Alisa knows and practices μ's choreography, often dancing at home and even teaching the routines to Yukiho.