The animation deals with the historical period from the marriage of Ko's parents Haemosu and Ryuhwa to his demise, in which Ko unified cognate minor-countries into powerful Koguryo Kingdom.

From part 1 to part 10, the animation tells a story that Ko was disillusioned at Puyo Kingdom and decided to escape from Puyo.

His father Haemosu tried to frustrate the outside forces' invasion, but fell a victim to a plot of Kumwa, king of Puyo. In order to conceal the truth behind the killing of Ko's father, Kumwa allows Ryuhwa to live in his palace and adopts Ko while putting forward Haemosu as a loyal man who dedicated his life to the country.

But Ko could not but rear horses with slaves after being slandered by Prince Taeso and his younger brothers who envy Ko's extraordinary talents and strength.

In this course, Ko comes to have hatred for the royal family and perceive that it is none other than common people who really love fellow countrymen.