|As a powerful empire rapidly extends its dominance, the world gets lured into a whirlpool of its ambition. The northeastern countries that were living in tranquility start to moan in suffering after they get attacked by the Khan Empire. Among those are Bu Yeo, which is the strongest from emerging nations, Jol Bon, a country at a verge of collapse, and Ha Baek, a country that was merely a tribal village. There was a mysterious myth among them that was passed down from generation to generation. At a time of great disparity, a legendary king will appear in bold red clothes to save them from their suffrage and establish a powerful empire named Ko.