柊 美紀

She is Mio's older sister and the president of Shiraba Academy. She took over the position after her mother retired a few years ago. She has a keen eye for cute things, and is especially fond of Mio.

She is often perceived as unreliable because she calmly goes at her own pace. However, she is able to switch personalities between her private and public life, and when she has to make a decision, she makes it decisively.

She is engaged to Rin Ougi, the president of Seiou Academy, and is planning to get married next spring.