She is Kobeni's elder sister, she has two persona's where she is an immature and a carefree loving sister at home, while in school, where she is the student council president, maintains her respectable popular image as a demure, well mannered and an elegant top performing student in front of her legion of fans. She has taken a liking to Mashiro that she would do all sorts of advances to her at home.

(Source: manga-reader)