Towards the end of the 13th century, the Mongol Empire devastated entire nations on its campaign of conquest in the East. The island of Tsushima is the only thing that still separates the Japanese mainland from the huge invasion fleet of the Mongols under the command of the merciless and cunning General Khotun Khan. When the island is in flames after the first wave of Mongol attacks, samurai warrior Jin Sakai is left behind as one of the last survivors of his clan. He is determined to do everything in his power to protect his people at all costs and reclaim his homeland. He must break with the traditions that make him a warrior, take a new path - the path of the spirit - and wage an unconventional war for the freedom of Tsushima.