|The Koga and Iga are two ninja clans that had been fighting each other for 400 years. Gennosuke of Koga and Oboro of Iga, love each other and have promised to break the cursed bonds of conflict. However, they are destined to kill each other.|
It is the 19th Year of the Keicho Era (A.D. 1614), and 73-year-old Ieyasu is wondering which of two brothers he should choose as his successor, Takechiyo or Kunichiyo. Takechiyo is the elder but he is stupid, while his younger brother Kunichiyo is clever. In order to choose the successor, Ieyasu decides to have the Koga and Iga clans each choose their ten best ninja to fight against each other. If the Koga ninja survive, Kunichiyo will succeed Ieyasu as Shogun. On the other hand, Takechiyo will become the next Shogun if the Iga ninja win.
As Hattori Hanzo the First had implemented a truce between the two clans, they haven't had a fight in years. Therefore, when the truce is broken, they go at each other as if they were unleashed war dogs. The only weapons they use are their own bodies. They possess special abilities that normal men can hardly imagine.
So begin the battles of twenty ninja, young and old, men and women. They make the most of their special abilities in these harsh battles and they are killed one by one. Which side, Koga or Iga, will win? Who will survive? What will become of the love of Gennosuke and Oboro, separated as they are by the conflict?