Ogen and Danjo recovered their past memories when they were young and the Kouga clan attacked the Iga village. But peace may not come toward the rival clans when the leaders (Danjo of Kouga and Ogen of Iga) both annihilate each other.
After, Oboro didn't go back to her village, a couple of ninjas from her clan go out to search for her. One member for the opposing sides go into a little chase for a scroll the hawk of the Kouga clan dropped by. When th eIga clan read that the scroll and find out that Ogen Iga and Danjo Kouga killed each other, they lie to Oboro and say that the war between the two clans have been resolved. However, that just means the start of war...
On their return trip to the Iga clan holdings, unexpected bounty is discovered in the wild: one of the Kouga ten, her life is spared for a darker purpose. But the Kouga have not sat idle, and seeking to learn the motivation behind the recent attack they stumble upon their own surprise catch. The truth struggles to find illumination despite the treachery.
Gennosuke grows wary as hostility mounts, while the other Kouga captive demonstrates dire consequence for the baser forms of assault. Warriors in disguise seek to unearth the hidden deception, the counterfeit aided by desperate belief. The Iga stronghold infiltrated, Oboro is called away to finally learn the truth. The way has been laid for grief.
Death stands in the path of the Kouga, waiting with baited breath, silent in the night breeze. The mentor's sacrafice ensures the pupil's safety, as Gennosuke is led to safe haven. Accompanied into the shades by recollections on what was, hope is shed on what may come to be. For the sun is glory, and it shines all over. Not just Kouga...but over the Iga people as well.
Tenzen's secret is revealed at last, the cost of which proves death to a Kouga in disguise. As Lady Ofuku's forces lend strength and protection to the two surviving Iga, they continue on their way to Sunpu Castle. Kagero claims responsibility for the death of Oboro seeking Gennosuke's affermation and affection. But when she sets out to prove her lie truth, trust misplaced will prove her undoing.
With Kagero captive, Oboro seeks a public challenge, seeking to call Gennosuke out, desiring to face him one last time. She stops Kenzen at his cruel play, unwilling to bear the suffering of an enemy and draws his wraith instead. But Gennosuke arrives to face Kenzen at last, forced to defend himself with his greatest weapon still sealed against him. A starling revelation rings out in the night.
Gennosuke cuts the serpent down at long last, the one responsible for fueling the enmity between the Kouga and the Iga for two centuries past. The one, whom among all others, will not allow peace between them. As they stand reunited, Oboro begs for death, unable in her love to stand against Gennosuke. But Kegero and Tenzen, each with their dying breath, set the final confrontation in motion.
Brought back to the very grounds where the travesty began, forced into this final conflict by political demand, Gennosuke and Oboro face one another on the field of battle. Gennosuke, wounded and poisoned, blinded still by the hands of the Iga. Oboro, unskilled in the arts of war and unwilling to prove false to her love. Neither with a care as to whom will inherit the title of Shogun.