L, an angel who’s endlessly fascinated with the human world, gets into trouble when she unthinkingly saves the life of Han Shi Yeong, a man who was meant to die. To make up for her mistake she must guard him on Earth for one hundred days and keep him safe from Hwan, a death god who is required to collect his soul. Both supernatural beings must contend with the knowledge that whichever one of them fails by the end of the hundred days will be erased from existence, and the longer they stay on Earth the further their powers fade and the more human they become.
33-year old Han Je In is a mystery novelist who is notorious for habitual false reporting to the police in town. Her only friend is police officer Rok Hwan, who has had a crush on her since childhood. One day, Je In hears a scream of help from an apartment upstairs and reports that a serial killer lives above her but no one believes her. Convinced that Jason, the handsome man living upstairs, is a serial killer, she asks Rok Hwan to help follow him around with her. But as she learns more about Jason in her pursuit to uncover the truth, she begins to fall for him. Seeing her in this state, Rok Hwan feels a tinge of jealousy.
Matsumura Ryouko is a popular novelist in her 50s who has just found out that she has Alzheimer’s disease. In order to gain some fulfilment in her life, she decides to be a guest lecturer at a university. Through one of her students, she meets a South Korean exchange student, So Chan Hae. As they become closer, they fall in love.
