Kawashima Sapphire is a character in Hibike! Euphonium. She plays the double bass in Kitauji High School's concert band, joining in the same year as Kumiko. Her bass skills are excellent, as she previously attended a private school specializing in music. Sapphire is is the name her parents gave her, but she finds that embarrassing and prefers to go by Midori (緑, first kanji of her given name).
Sapphire has short blonde hair and brown eyes. At 148 cm, she is substantially shorter than most of her peers. Sapphire is close friends with Katou Hazuki.