For centuries, the Iga and Kouga ninja clans have engaged in a bitter war. But when a ceasefire is ordered by the powerful warlord Ieyasu Tokugawa, the two clans are forced to put down their arms. Years later, Gennosuke Kouga, heir of the Kouga clan, and Oboro Iga, heir of the Iga clan, have fallen in love. Through marriage, both heirs aim to bring peace to the clans. But their hopes are dashed when flames of rivalry...