Ji-O has a special power and a secret, but he doesn't know who he really is. He is chased by mysterious figures, while he tries to find answers to numerous questions that surround him. Goo-Reum is a detective. When she decides on a course of action, she won't change no matter what. Her parents disappeared when she was only a young child. Goo-Reum chases after the truth behind her parents' disappearance. She meets Ji-O and her life changes.

Bok-hui and Mal-ro are not your average housemates. Bok-hui has a crush on Mal-ro. The problem is that Bok-hui is a ghost and Mal-ro is not. Besides, Mal-ro is not attracted to Bok-hui. In order to get rid of Bok-hui, Mal-ro tries to introduce her to a bachelor ghost Sang-won. To Mal-ro's surprise, Sang-won falls for Mal-ro, too!