Set in the ancient Kingdom of Ayothaya, this incredible true story brings to life the adventures of Yamada Nagamasa, a young Japanese Samurai warrior, who gave up his homeland to protect the sovereignty of the Thai people. Betrayed and left for dead by treacherous Japanese forces, he finds a new family in a remote village and masters the devastating fighting art of Muay Boran (Thai boxing). Fearless, he ascends to the royal bodyguard of King Naresuan The Great, but will soon face his greatest ever battle against the elite Japanese warriors he once regarded as brothers...