Mikino Oka (岡 美貴乃 Oka Mikino ) is a minor character in the Hibike! Euphonium series. She is a third-year student who plays the bassoon. She seems to have a good relationship with Raina Kitamura, who is also a bassoonist.
Mikino is a considerably tall girl with curly black hair held up in a ponytail with a green bow, and has purpleish-blue eyes. Mikino is usually seen with a normal Kitauji High School uniform for third-year female students.
Mikino is not shown expressing much emotion in the show, usually having a serious facial expression.