In the distant past, the "land of the Middle Plains" in the eastern part of the continent was divided into several countries and fought against each other, and the world was in turmoil. Xiaotian (Shouten), a swordsman at the Leopard Bureau, a guard business that protects his clients from rampant bandits, meets a boy named Jingyue (Keigetsu)and a young man named Zhu Jun (Shu Jun) from an incident. However, the two of them have an unexpected secret...!