The series tells the love story of Han Se Gye, an actress who must spend one week out of each month living in someone else's body, and Seo Do Jae, a man who suffers from Prosopagnosia.

A woman changes her appearance whenever a certain supernatural phenomenon occurs. A man falls in love with this woman. Han Se Gye is a top actress. She is known as a troublemaker and the object of many rumors. Her life is a mystery, but, in reality, she suffers from an unusual phenomenon. At a certain point every month, her appearance changes to a different person. She lives one week out of every month with a different appearance. Han Se Gye meets Seo Do Jae. Seo Do Jae is an executive at an airline company. He seems perfect with an attractive appearance and possessing smarts, but he suffers from an inability to recognize faces. He hides this disability and tries hard to memorize people by their habits and mannerisms. The only person's face that he is able to recognize is Han Se Gye. By meeting her, his life changes.—(Source: AsianWiki)