Upon turning 18, Beomgyu receives an angel and demon that influence his decisions. Angels and demons have been in a continuously battle for the possession of humans, and are using Beomgyu for their claim. But even in heaven, things don't always as planned. Shortly after being assigned to the boy, angel Soobin and demon Huening Kai begin to slowly blur the lines between good and evil. Through a maze of change and self-discovery, the three discover that life might not be as black-and-white as it seems.
13 parts