Katsura Kotonoha♀

Polite and reserved, Kotonoha Katsura is a student in year one of class four who is on the student council and serves as one of the most pivotal characters in the story. A cute and noticeably well-endowed bookworm, she becomes the initial love interest of Makoto early into their second term, and with some effort from Sekai Saionji, becomes his girlfriend after she reciprocates her affection for him. While Kotonoha for the most part is calm and gentle, she has a very delicate conscious, which under stress leads to irrational culpability, delusions and even malice. She has a younger sister name Kokoro and lives with their wealthy mother Manami and father in the fictional area of Haramihama. She is disliked by Otome Katou and is subject to her bullying and duress.

[From Wikipedia]