The bloody battle to rule Japan has begun: the Iga and the Kouga clan are locked in a fight to the death. Driven by a centuries-old hatred, the clans will do anything to annihilate each other. The Kouga clan is engaging in a little espionage and has planted a shapeshifter, disguised as an Iga ninja, in the Iga palace. Meanwhile, the Iga clan turns to its last, best hope: their new leader, Oboro, who alone can defeat the Kouga's formidable leader, Gennosuke. But is Oboro willing to kill the man she loves?

As the war grows more desperate, true love may be the next casualty...