In 1614 A.D. - Ieyasu Tokugawa created a treaty that kept the Kouga and Iga ninja clan in peace for years. But after dismantling in the treaty, it results in bloodshed and annihilation between the two clans. A war breaks out when a member of the Kouga clan - Gennosuke Kouga has an arranged marriage with Oboro of the Iga clan. The story is about 10 ninja from each clan, that possesses inhuman abilities and techniques. However, they are still mortal beings.