Exiled prisoners join forces with samurai clans on Tsushima Island to defend against the Mongol invasion of Japan in 1274, fighting Mongolian, Goryeo, and Jurchen forces.

The story follows a group of prisoners who are exiled to Tsushima Island to help form a first line of defense against the first Mongol invasion of Japan in 1274. They first join the So clan who then join with the Toi Barai clan to fight the invaders consisting mainly of Mongolian and Goryeo forces, but also including Jurchen people.—Moh-X