Keiko Sasahara

Keiko is Kanji's little sister, who leads a kogal lifestyle. She carries a blatant crush on Kousaka, much to Saki's chagrin. She even tries to become an otaku and gets drawn into the otaku world (to a point) when she seems to like some of the dōjinshi Ohno shares with her. In volume 6, she moves into Kanji's place so that she can take the entry exam for Shiiou University and fails, but she gets into Ohka Business College nearby. Her sole reason for doing so is in order to join Genshiken and be closer to Kousaka.

(Source: Wikipedia)