Kuko Yasaka, also known as Cthugha, is a prominent character in the anime series 'Haiyore! Nyaruko-san.' She is a humanoid alien from the planet Cthugha and serves as the main rival and friend of Nyaruko. Enthusiastic and fiery, Kuko has a deep, intense affection for Nyaruko, often leading to comedic and chaotic situations. Despite her assertive personality, Kuko is loyal and protective of her friends. Throughout the series, she balances her feelings for Nyaruko with her duties as an alien, providing humor and excitement in her interactions with the other characters.