Hyun-ryeong, the leading character, lives on the border between the living and the dead because his heart had been exchanged with that of a monster called Guiho when he was born. As a series of mystery killings continue in his village, a powerful shaman and a mysterious girl, Gapjin, make a visit to the village. Hyun-ryeong’s elder brother Hyool-ryeong kills the shaman with a vengeance when he is suspected as the culprit of murders due to the shaman. Hyool-ryeong takes Gapjin, who is then left alone. He learns from Prince Sado that Mr. Oh, a merchant from Qing, and a monster Guiho who has taken his heart, are involved in a series of murders in the village. Prince Sado asks Hyun-ryeong to get rid of Guiho. A period drama fantasy romance, The beginning of Hyun-ryeong and Gapjin’s adventures who want to recover their heart.