Kirino Kousaka

Kirino Kōsaka (高坂 桐乃, Kōsaka Kirino) is the main heroine of the series. Kirino is Kyousuke's younger sister and the youngest of the two siblings of the Kousaka family. She is an overachiever who seemingly lives a perfect life and is idolized by almost everybody. However, she keeps a big secret from her family — she is an avid otaku and a fan of adult-rated games, especially those involving brother-sister dynamics.