Once a powerful ninja, Kamui walks away from his violent and murderous ways. His travels bring him to a seashore village where he meets Hanbei, a fisherman who shares the former ninja's sense of honor. Though Hanbei's wife is wary of the stranger, the fisherman and Kamui become good friends. Life at the seaside seems idyllic but Kamui doesn't get to enjoy the peace for very long when, one day, a band of pirates arrive... It seems that his past life is catching up on him, and everything and everyone is not as it seems. Now he must draw upon his shadowy arts if he hopes to escape with his life.

When a powerful warlord in medieval Japan dies, a poor thief recruited to impersonate him finds difficulty living up to his role and clashes with the spirit of the warlord during turbulent times in the kingdom.