Orphan Jinha begins training in the Bichun martial arts (taught by his apparent aging uncle) and discovers his father was a noble swordsman of a renowned House, murdered by the Mongol army, led by Korean rivals seeking the secrets of the Bichun martial arts.

As told by his dying uncle, who at his death bed reveals his true identity as one his father's guards, Kwakjung, suffering from a wound by assassins.

After his rescue by a fisherman and recovering from near-death, Jinha takes on the persona of bandit Jahalang, and begins an anti-Mongol crusade with the help of his rebel army of Bichun warriors.

After multiple successes across the kingdom, Jinha personally ambushes and kills the aging Mongol general in a ritual execution, as revenge for being one of those behind the plot against his family.

[6] In spite of its financial success, the film was heavily criticized on its initial release in Korea, primarily due to its alleged disloyalty to the comic book on which it was based.