In Hanyang during the Joseon era, the people suffered under the exploitation of corrupt officials, while the real power of the court fell into the hands of treacherous subjects. Hong Gil-dong (voiced by Kim Min-jong), who possessed exceptional martial arts skills but was unable to take the military examination due to his status as an illegitimate son, disguised his identity to take the exam and passed. However, his true status was eventually exposed, causing him to fail and leave home. Hong Gil-dong meets Chadolbawi (voiced by Yoon Seok-hwa), who has become a vagabond due to the exploitation of corrupt officials, and heads to Geumgang Mountain in search of the Hwalbindang. There, he meets Baekun Taoist, who is gathering people to set the world right, and learns martial arts from him. Golban Taoist creates a cult with himself as its leader, seizing temples across the country in an attempt to take control of Joseon. Meanwhile, the treacherous official Im Sa-hong, who covets the throne, joins forces with Golban Taoist to plot a scheme to seize royal power. To create an opportunity for their rebellion, Golban Taoist and Im Sa-hong organize a national martial arts tournament. They plan to have Golban Taoist's skilled subordinates participate, eliminate all the martial arts masters in the country, and use the chaos as a chance to assassinate the king in a coup. Gopdani, the daughter of the treacherous Im Sa-hong, who is unaware of her father's wickedness and schemes, secretly admires Hong Gil-dong and watches from the crowd. As the treacherous Im Sa-hong and the ailing king observe together, Golban Taoist's disciple Hopi (voiced by Shin Hyun-joon), Golban Taoist's subordinates with immense power and deadly techniques, and Hong Gil-dong, disguised as a mysterious man, step into the martial arts tournament arena at Gyeongbokgung Palace.