At the beginning of the story, Erin is a 10-year-old girl who lives with her mother in the Tai Koh Region. She has a big love for animals, especially the Touda, dragon-like creatures used in the war. Her mother Soyon was originally of the Mist People, an ancient clan whose members have green eyes. Because Erin's late father was the son of the chief of a village of Touda breeders, Erin and Soyon live there and Soyon is the head Touda doctor. But one night, the Kiba, the Duke's strongest Touda, mysteriously dies, and Erin's life will be changed forever, involving her into the fate of the whole country. The series tells the story of Erin's life from childhood into adulthood.