Yuki Nagato is a fictional character from the anime and light novel series The Melancholy of Haruhi Suzumiya. She is known for her quiet demeanor and distinctive appearance, characterized by her long, dark hair and red eyes. Yuki is an alien interface created to observe and interact with humans, possessing advanced abilities such as telepathy and manipulation of matter. In the series, Yuki is a member of the SOS Brigade, a club formed by the protagonist, Kyon, and the eccentric girl Haruhi Suzumiya. Despite her reserved nature, Yuki plays a crucial role in the story, often using her powers to protect her friends and maintain the balance between different realities.