It is the year 972 A.D. in Kyoto, ancient Japan's capital Kyoto is becoming a corrupt and run-down city, teeming with greedy samurai and onmyoji intent solely on attaining political power. To make matters worse, the city is plagued by starvation and sickness. Unable to overlook the city's state any longer, the Imperial Court dispatches Minamoto no Raiko, a famed warrior known for his archery abilities, to acquire a mythical jewel thought to contain secret power to rescue the world. Raiko, on the other hand, becomes unwell as a result of illness. Hikaru, his younger sister, instead decides to make the trek in his place. Hikaru meets a lot of people and has a lot of experiences in her quest for the famous diamond.