Kirino is Kyosuke's 14-year-old younger sister. She is mature for her age with a cold, tsundere-like personality. She is secretly an otaku with an obsession for "little sister"-themed eroge, as well as the children's anime series, Stardust Witch Meruru. She works as a photoshoot model and later becomes a novelist, the funds from which she uses to support her hobby. Despite her interests, she states she does not know why she started liking it and denies having a brother complex, believing the 2D and 3D worlds should be kept separate.