Now

Before the collapse of the Korean Kingdom of Goguryeo, a solitary figure traveled the region, unleashing unprecedented destruction through an unfamiliar martial art known as Sa Shin Mu. Peace returned unexpectedly, and it was said that the warrior was killed by his younger brother, the only one to have fully mastered the technique. Soon after, both the warrior and all knowledge of Sa Shin Mu vanished without explanation. Two decades later, following the kingdom's fall, a new rumor claims that a hidden manual describing the martial art has reappeared. Whether Sa Shin Mu will influence the future remains uncertain.