Third-year high school student and club president. Plays the euphonium. Particularly close with Reina, Hazuki, Midori, and Shuichi.

Third-year high school student who transferred from Seira Girls' High School in Fukuoka. Plays the euphonium. She gets along with everyone but feels slightly out of place in the concert band club because she treats it as "just a club."

Third-year high school student with a bright personality who gets along with everyone. Plays the tuba and is steadily improving. Close friends with Kumiko, Reina, and Midori.

Third-year high school student with a bright personality. Plays the contrabass. Close friends with Kumiko, Reina, and Hazuki. She dislikes being called "Sapphire" and asks people to call her "Midori" instead. She uses polite speech with everyone.

Third-year high school student. Strict during practice but cares deeply for her friends. Drum major. Plays the trumpet. Close friends with Kumiko, Hazuki, Midori, and Shuichi.

Third-year high school student and vice-president. He likes Kumiko. Plays the trombone. Close friends with Hazuki, Reina, Kumiko, and Midori.

Second-year high school student with a cheerful personality. Plays the tuba. Calls Mirei "Micchan." She absolutely adores Mirei.

Second-year high school student who speaks her mind. Plays the tuba. She used to hate being called "Micchan," but after being persuaded by Kumiko, she accepts it now. She calls Satsuki "Sacchan."

Second-year high school student with a bit of a sharp tongue. Plays the euphonium. She calls herself cute, to which Kumiko usually replies, "Yes, yes, you're very cute."

A bit blunt but a dedicated teacher to his students. Formerly played the trombone.