When fourteen-year-old samurai apprentice Seikei is sent on a mission by the shogun, he believes it to be a simple one: convince the fourteen-year-old emperor to resume his ceremonial duties. But then the emperor is kidnapped, and Seikei finds himself in the middle of an elaborate plot to overthrow the shogun. With the help of a mysterious warrior, he must rescue the emperor before the sacred sword—said to be unbeatable in battle—falls into the wrong hands. Seikei knows he must succeed, or bloodshed will stain the land.