At the peak of the Heian Era, famine and disease tear the country apart, deadly assassins fill the court, and wild bandits infest the countryside. The legendary samurai Minamoto is sent on an Imperial quest for an artifact that can restore the world. But his skill with the bow cannot save him from illness, and his young sister is forced to take his place.

Hikaru Minamoto and her companions embark on a quest to find the Magatama to bring new life to Japan. Her survival in the emperor's court depends on one thing — she must keep her true identity hidden.