When high school student Kim Eun Mi discovers she is pregnant, her whole life changes in an instant. Determined to keep her baby, Eun Mi did just that. Raising her daughter Jin Hee on her own, the two literally grew up together. Today, at forty, Eun Mi works as a physical therapist, while twenty-nine-year-old Jin Hee works as a police officer at the Namchon Police Station. Although she is now an adult, Jin Hee still lives with her mother—a fact that leads to an endless series of squabbles between the two. Although both mother and daughter agree that they love each other deeply, the two cannot seem to find a way to get along. As if the struggle to find a way to deal with her daughter weren’t enough, Eun Mi’s life takes a complicated turn when Dr. Park Jin Hong suddenly appears before her. While Eun Mi tries to make sense of the mysterious Dr. Park, Jin Hee struggles to find a way to get along with her new director, Eun Jae Won.