An American businessman, Paul Racine, finds himself embroiled in a dangerous game of life and death after a chance romantic encounter in Japan. While on a business trip in Nagoya, Racine spends the night with a mysterious woman named Kirina, only to witness her brutal assassination by a notorious hitman, Kinjo, that same night. Unbeknownst to Racine, Kirina was the target of an ancient and influential ninja cult led by Kinjo. Racine's involvement now makes him a target, as he is the only Westerner to have seen Kinjo's face and lived.

Hunted by the relentless ninjas, Racine must navigate a foreign land's urban dangers and rural terrains with unfamiliar customs, all while eluding death's swift approach. He reluctantly partners with a seasoned samurai, Takeda, who holds a deep-seated grudge against Kinjo and the cult. Together, they embark on a perilous journey, attempting to stay one step ahead of the cult members while seeking to bring Kinjo to justice. As Racine is plunged further into this deadly conflict, he transcends his role as a mere witness, becoming an active participant in a centuries-old blood feud that tests the limits of his endurance and will to survive.