Himeko Momokino

Himeko is the Student Council vice-president and Mei's childhood friend.

She has a rather stuck-up and stubborn personality and despises people who don't follow the school regulations. Despite her taste of sticking to the rules, she seems to enjoy lolita fashion, as she is usually seen wearing that kind of clothes when not in school.

Himeko gets extremely jealous and overprotective of Mei and absolutely abhors Yuzu's close relationship with her. It is popularly believed that she harbors intense romantic feelings for Mei, and often emphasizes her relationship with Mei by continuously referring to the fact that they were both childhood friends. Despite her seemingly yandere-like personality, she does have Mei's best interests at heart as she begrudgingly accepts Yuzu's attraction towards Mei. However, that does not stop her from frequently complaining about Yuzu's terrible behavior.

(Source: Citrus Wikia)