Korea, 1724. Once upon a time in the Joseon Dynasty, Chun-doong (Lee Jung-jae) meets a beautiful woman while in the middle of a fight in an old market. Having fallen in love at first sight, good fortune is with him and he finds her once again. Her name is Seol-ji (Kim Ok-bin) and she works as a gisaeng, a Korean traditional singing and dancing girl. They spend a memorable night together but Chun-doong loses her again when she moves to work at another bar. When he finds her new hiding place, however, he is warned away by her new manager, Man-deuk (Kim Suk-hoon) who has connections in the city's underworld. One day, while still despondent without Seol-ji in his life, he accidentally knocks over and kills the boss of the Jjak-gwi gang. Before he knows it, because of his fighting skills Chun-doong becomes the replacement boss. Soon, there is a gathering of the region's gang bosses at the bar where Seol-ji now works. In the middle of the meeting, Chun-doong causes a disturbance to steal Seol-ji away under the nose of Man-deuk. The meeting turns into chaos because of the incident and ends abruptly. A furious Man-deuk teams up with rival gangsters to plot the downfall of the Jjak-gwi gang..
This drama portrays the life of the 19th king of Goguryeo, Hwanwoong, who was sent from the heavens to make the world a better place. He falls in love with Saeoh and gives her the joojak necklace; however, Kajin becomes jealous since Saeoh has given birth to Hwanwoong's son. She takes the baby and throws him off a cliff. Saeoh, thinking that her son had died, is overcome with grief and turns into the black joojak to destroy the world. Hwanwoong is the only one who could stop her. Afterwards, Hwanwoong returns to the Heavens and prophecizes that 2000 years later, the true Joo Shin king will come to Earth. With the help of the four gods, he will rebuild Joo Shin.