Two tribes sworn to hate each other, the Kouga and the Iga. The Year: 1581 A.D. Danjou - sama of the Kouga and Ogen - dono of the Iga are in love and they have to meet in secret because none of their tribes would approve their love. 
Their dream is to make peace between their tribes so they can live happily together. Both try to convince the leaders of their tribes to make peace and they believe that they are really close in achieving this. They meet one last time in secret and during their meeting they get to witness an attack to the Tsubagakure village (Iga village). They both run to help the villagers and when they get there they find out that the attack was made by the Oda. Just before they found out that the elder of the village is dead Ogen got shot so they decided that they must retreat among the other Iga that survived.
While trying to escape in the forest they get attacked by other Kouga led by a ninja called
Renbu. Danjou - sama ordered them to stop and demands explanations. Renbu explains to him that the elder told them not to obey him and that he ordered them to use this opportunity in order to exterminate the Iga. Ogen - dono then realises that peace between the Iga and Kouga is not possible and that their love is not meant to be and she attacks Danjou - sama.
Year 1614 A.D. 73-year-old Ieyasu was wondering which of the brothers he should choose as a successor, Takechiyo or Kunichiyo. In order to do that he decided to give Iga and Kouga a reason to fight and break the truce which Hattori Hanzo the first made them achieved. Both 
tribes had to choose their 10 best ninja to fight till death. If Kouga win then Kunichiyo would become the next Shogun and on the other hand if Iga win then Takechiyo would become the next Shogun. The winning tribe would also achieve the annihilation of the other tribe and the support of the Tokugawa government for a thousand years. Ieyasu invited Ogen - dono and Danjou - sama to bring one of their best ninjas to fight for a demonstration. After a short fight he announced them his plans and he gave them four scrolls to inscribe the names of the 10 ninjas of each tribe. They both accept and the fight begins!
Ogen - dono and Danjou - sama meet for one last time and discuss about the love of their grandchildren Gennosuke and Oboro and that their will probably have the same fate their own love had. Ogen - dono then dropped her defense and then Danjou - sama found a chance to attack her and kill her by throwing to her a blade. While Danjou - sama was erasing her name from the scroll Ogen - dono found strength to hit him back and kill him. They both lay on the floor dead and 9 ninjas from each tribe remain for the fight. Which tribe will win? What will happen the love of Gennosuke and Oboro who now have to kill each other?