Directly from the back of the first cover:

--During the epic battle of Sekigahara, two samurai face off outside of histor. The heated duel between Kyoshiro and Demon Eyes Kyo is interrupted when a falling star slams into the plains, shattering the ground and engulfing both of them. Years later, Kyoshiro, now a medicine man, wonders the land with a forgotten past. Hidden deep inside him is the soul of his old opponent, Kyo, slayer of one thousand men.--