A 10th-grade student at Umimaku High School. Born on February 6th, he is in the same grade as Hajime Aono. A returnee who lived in Germany until around age 12, he has shown talent for the violin since early childhood. With enough skill to win numerous competitions since middle school, he entered Umimaku High on a music scholarship. He plays 1st violin in the high school orchestra and is one of Hajime Aono's most prominent rivals. He has a bright, laid-back, and somewhat aloof personality. He doesn't get swept up in the atmosphere around him and maintains his own pace, sometimes giving the impression of being elusive. He is also a bit airheaded and clumsy, creating a charming gap between his personality and his genius-level violin skills. His sense of personal space is unique; while he speaks his mind honestly, he also has a sensitive side that observes others closely. He is extremely serious about music and possesses a strong core when pursuing his own sound. Though he usually appears carefree, he harbors worries and complex emotions deep down, revealing a delicate and awkward nature.

10th-grade student at Umimaku High School / Orchestra Club Part: 2nd Violin A bright, proactive girl with a very strong sense of justice. She often clashes with others because she speaks her mind directly, but she is also a hard worker who never gives up. She is a beginner who started the violin in the fall of her 9th-grade year. While attending school in the nurse's office due to certain circumstances, she met the protagonist, Hajime Aono, a former child prodigy. Her earnest, albeit clumsy, playing became the catalyst that moved Hajime's heart after he had quit music.

10th-grade student at Umimaku High School / Orchestra Club Part: 1st Violin Kind-hearted and gentle, but possesses a very reserved and hesitant personality. She has been best friends with Ritsuko Akine since they were in the same class in middle school. She met Hajime Aono at a music competition when they were in elementary school. After he spoke to her while she was crying over a loss, she developed a secret crush on him.

Orchestra Club Part: Cello A friendly mood-maker: bright and active with many friends, he proactively approached Hajime Aono, who tended to distance himself from others, and became his friend. He was classmates with Nao in middle school and they have been close since then. Yamada has played the cello since childhood and was confident in his skills, but he has a history of having his pride crushed after hearing Nao's overwhelming violin performance in middle school.

10th-grade student at Umimaku High School: Orchestra Club (1st Violin). Karen's older brother. Having received elite education from his father, the world-renowned violinist Ryuji Aono, he is a former child prodigy who excelled in numerous competitions. He is extremely competitive but struggles with academics and sports. Due to past trauma, he initially had a tendency to distance himself from people.