Ashikaga Chie

Willful yet caring, Chie Ashikaga is the older sister of Yuuki who, like Roka, is a member of the woman's basketball team. She introduces her brother to Roka in the beginning of the game, initiating the first love triangle of characters and the basis to what eventually becomes a misunderstood affair between Roka and Makoto. Chie is good friends with Ion, Youka and is jealous of Nanami Kanroji's athleticism.

From Wikipedia