Kitsuregawa Roka

Roka Kitsuregawa is a student in year one of class two who is a member of the woman's basketball team and serves as the main heroine of the story. Tender and friendly, she initially comes upon Yuuki in the school library, and, following a more developed acquaintance through his sister Chie, becomes attracted to him. Like Yuuki, Roka herself is also short and petite, standing roughly his height and equally as intimidated and timid. She is friends with Chie, Ion Ishibashi, and Youka Kira.

From Wikipedia