Mark, the gay CEO of an entertainment company, is killed and is given 100 days as a ghost to settle his unfinished business. Cin is a kind shy woman who lives a harsh life with her brother Sun and cruel stepmother and stepsister. Mark discovers he can possess Cin, and together they set out to help Mark's family and business, and solve the mystery of his death (with help from his brother Mate). Along the way, Mark helps Cin improve her own life and find love.