Ruri is a 15-year-old otaku girl who lives near Kirino and later enrolls into Kyosuke's school. She often wears gothic lolita clothing based on a character from her favorite anime, even during hot weather, and will sometimes add cat ears and a tail. Due to both of their tsundere-type personalities, she constantly clashes with Kirino. However, both girls genuinely care for each other and value the time they spend together. Kuroneko is very prideful like Kirino, but is willing to swallow her pride to achieve a goal. Unlike Kirino who likes little sister-themed games and magical girl anime, Kuroneko enjoys teen-centered fantasy anime.