This is a series surrounding the teenage twins Aya and Aki Mikage. On their sixteenth birthday, the two are invited to their grandfather's home for what appears to be a party. When they arrive, a test brings out something in Aya that frightens her and threatens the existence of the Mikage clan. This series depicts the events that occur when this being begins her search for what rightfully belongs to her, her Hagoromo. The Episode Guide contains many spoilers. This show has never been aired in the United States.