Kotone Kirishima (桐島 琴音 Kirishima Kotone) is the daughter of Keizou Kirishima (a Buddhist monk) and the older twin sister of Akari.

Despite her gentle and sweet outward demeanor, she is interested in Junpei Kōsaka mainly because of his misfortunes, and can be considered sadistic, delusional, and an obsessive stalker. In the anime, she is shown to have this sort of behavior even at a young age towards one of her teachers. She also shows her jealousy if another girl gets too close to Junpei.