Cure Cosmo is a major magical girl character in Star Twinkle Precure, known for her mysterious background and strong combat abilities. She is an alien heroine who initially appears as the cat-like mascot Yuni before revealing her true identity as a Precure. Throughout the series, she serves as a key ally to the main team, helping them protect the universe from threats. Her role emphasizes independence, courage, and the importance of trust and friendship.