Kuuko is a love rival from Nyaruko: Crawling With Love female Cthughan (alien from the distant planet Cthugha). She takes the form of a slender, red-haired girl in her teens. Her defining trait is her love for video games and Nyarko. She is usually the comic relief character when Nyarko isn't. She is in love with Nyaruko despite that her race is the archnemesis of Nyarlathotepians, and appears to be clingy that she is hostile toward Mahiro and threatens him to stay away from Nyaruko in the beginning of the story. As the story progress, she becomes more friendly towards him. She transfers to Mahiro's school and takes the name Kūko Yasaka, Nyaruko's "wife". She is also obsessed with otaku culture and video games. Kūko was Nyaruko and Hasuta's space elementary school classmate and appears to at the same age as them, although she became a NEET after graduating from high school, and become a Space Defense Agency agent and colleague to Nyaruko later by using the relationship of her uncle who is an employee in the human resource department of the Space Defence Agency. She concealed her feelings for Nyaruko from her family and lied to them that Mahiro is her fiance, as love between Nyarlathotep and Cthugha are considered a shame of the family among Cthughans. She possess the power of fire, able to control fireballs, heat, or drones that fire lasers; she refers to them as space CQC - Cthugha version. Her strength in combat is lower than that of Nyaruko's. Her combat form is covering her lower body with red fire patterns.