Shikishima Kyou (敷島鏡)

The hikikomori resident of one of the dorm's rooms, she is a devoted otaku who frequently speaks in anime/eroge/manga slang and seems to be incapable of fully separating reality from her hobbies. She mistakes Yuuma initially for her older brother, and even when she realizes that he isn't, she continues to call him onii-chan, for obscure reasons of her own.