Asagi is a hanyou, and a protagonist in the film Inu Yasha: Fire on the Mystic Island.
She lived on a magical island, far off the coast of Japan. This island was once a paradise, where humans and benign demons lived together in peace and harmony. For this reason many half-demons were born there. But one day, four powerful and evil youkai captured the island, killing almost all of the villagers.
At the time of the plot, Inuyasha and his friends came across this island. They also meet Asagi, who is to be sacrificed next by the four youkai, so that they can get their strength. Inuyasha can save Asagi, then fight with his friends against the evil youkai who have conquered the island.
When these youkai are destroyed, Asagi and her friends can leave the island. They are looking for a remote place in the mountains, where they can live in peace and harmony.