Nia Teppelin is a pivotal character in the anime series Tengen Toppa Gurren Lagann. Initially introduced as a mysterious girl found in a box, she becomes a significant figure in the battle against the Spiral King. Nia is known for her kind-hearted and curious nature, often questioning the world around her. As the story progresses, she discovers her true origins and plays a crucial role in the rebellion against oppressive forces. Her relationship with Simon, the protagonist, is central to her character development, serving as a source of strength and emotional depth.