Both dramas are about a set of people that have to fulfil a specific amount of demands in order to be spoken free of their sentence. In both dramas this group of people is either gods or grim reapers that are following/guiding through the judgement of people that have sinned. Both are supernatural stories dealing around death, the after life, hell/heaven, sins and forgiveness.
Kang Bit Na is an elite judge with a beautiful appearance, but she is a demon. Her mission as a demon is to kill evil people who lead other people to their deaths and don't reflect on their actions. She sends these people to Hell afterwards. One day, Kang Bit Na meets Han Da On. He has a friendly and gentle personality. As a detective, his mind is sharp and he has a keen sense of observation. But he carries a pain inside that nobody knows about. After Kang Bit Na and Han Da On meet each other, their lives change greatly.