Sapphire Kawashima(川島 緑輝Kawashima Safaia) is one of the main characters of the Hibike! Euphonium series. She is a classmate of Kumiko's and Hazuki's, and she is a contrabass player in the Kitauji Concert Band. Sapphire also dislikes her real name, preferring to be addressed as Midori(緑).