The story of a grim reaper who gets erased from the memories of the world for breaking the rules of heaven and falling in love with a mortal woman after inhabiting a human body.

Set during the Silla dynasty, Sam Maekjong is the son of the fallen king and present queen regent, Jiso, but he has been kept in hiding for protection ever since he was a young boy, when his father was murdered. Over the years the powerful nobles have tried and failed to usurp power from Jiso, causing her to grow wary and later even reluctant to hand the throne over. As her son comes of age, she creates the Hwarang, an elite group of male youth who train in fighting and education. Their existence cuts across the existing power factions and Sam Maekjong is amidst their ranks under the false name Kim Ji-Dwi, unbeknownst to other Hwarang members.

HONG Gildong is an infallible private detective with an exceptional memory and quirky personality. While chasing the only target he failed to find, he gets entangled in a much bigger conspiracy than he bargained for.

A Princess in the Joseon Dynasty travels to the Qing Dynasty to marry. On the way to there, she meets a young magician and falls in love with him.