Shigure Komai

A third-year student and Chizuru's older sister. She is beautiful, intelligent, and serene with a good grip on things. She could easily be a class leader but chooses to go straight home after school instead. She is deeply in love with Chizuru but is much more subtle about her feelings and even tries to suppress them, though she eventually gives in after going to Shinobu for advice and realizing that both her and her sister's feelings are too strong to ignore. (From Wikipedia)