Kousaka Kirino♀

Kyousuke younger sister. She is a 14-year old girl who seems normal on the outside, but is in secret a hardcore otaku obsessed with anime and visual novel eroges, especially those involving little sisters. She works part-time as a model, which is how she managed to purchase her most impressive collection of figurines, visual novels, and anime DVDs. She has a talent for writing, and loves track and field. She is initially cold and disrespectful towards her brother Kyousuke, but after he discovers her secret hobby and he supports her in it, they gradually grow closer

[From AniDB]