The time is A.D. 927, when Georan invaders conquered the ancient Korean capital of Balhae and set up a new country, Dongran Guk. The leaders of Balhae desperately need a royal figure to reunite their nation. They find a prince, the previously exiled Dae Jeong Hyeon, who's hiding out under the name So Sam.
The leaders dispatch a peerless swordswoman, Yeon So Ha, to protect So Sam before Georan's Killer Blade Army,
