The year is 1859, feudal Joseon is plagued with numerous natural disasters, poor harvest, poverty. hunger and death. But the rich nobles are only concerned with their own wealth and continue to exploit and persecute the poor. In this dark period, KUNDO, a righteous group of thieves, was a single shred of hope for the poor, an entity which can be the subject of fear to unjust nobles.
Joo Yoon is the son of a wealthy nobleman, but his mother is a concubine. Even though he excels in martial arts, he isn't recognized for his talents because of his lineage. After killing poor butcher Dol Moo Chi's mother and sister, millionaire Joo Yoon commands absolute power over him. Clouded by vengeance, Dol Moo Chi is accepted as a member of KUNDO and unsheathes his sword for the weak.