Kagami Hiiragi is the older fraternal twin sister of Tsukasa Hiiragi. In school, her grades are excellent, as she studies very hard,and she was elected class president in her first year. She is in a different class than Konata Izumi and Tsukasa, but she frequently comes to their class during lunch time to eat with them. Additionally, Kagami chose the humanities stream in her second year, so that she could be with her friends, but she was the only one separated into a different classroom; the same occurred in her third year. Kagami, occasionally referred to as "Kagamin" by Konata, is a bit egotistical, and not as good a cook as Tsukasa.