Set immediately after the Japanese Sengoku period, Iga and Kouga, two mercenary clans have been waging a vendetta against each other over hundreds of years. Around 1614, Tokugawa Ieyasu, the ruler of Japan and the founder of the Tokugawa Shogunate, perceives the threat posed by the two clans. Attempting to consolidate his reign, he deliberately stirs up their feud by inviting the clans to choose their five best warriors to fight to the death. Designated as the leaders of the two clans respectively, Kouga Gennosuke (Joe Odagiri) and Oboro (Yukie Nakama), who have secretly married, are unwillingly embroiled in the political plot. Hence, they have to make a difficult decision.