Based in Shinmiyangyo, or the U.S. expedition to Korea in the late 19th century, Mr. Sunshine tells the story of a Korean boy born into a family of a house servant running away to board an American warship, later to return to his homeland as a U.S. marine officer. He ironically falls in love with an aristocrat’s daughter and discovers the dark scheme to colonize the country that he once ran away from.

Based on actual events that took place at Gwangju Inhwa School for the hearing-impaired, where young deaf students were the victims of repeated sexual assaults by faculty members over a period of five years in the early 2000s.

Kyung-chul is a dangerous psychopath who kills for pleasure. He has committed infernal serial murders in diabolic ways that one cannot even imagine and his victims range from young women to even children. The police have chased him for a long time, but were unable to catch him. One day, Joo-yeon, daughter of a retired police chief becomes his prey and is found dead in a horrific state. Her fiance Soo-hyun, a top secret agent, decides to track down the murderer himself. He promises himself that he will do everything in his power to take bloody vengeance against the killer, even if it means that he must become a monster himself to get this monstrous and inhumane killer.