When high school student Kim Eun Mi discovered that she was pregnant, her entire life changed in an instant. Determined to keep her baby, Eun Mi did just that. Raising her daughter, Jin Hee on her own, the two have quite literally grown up together. Now in her forties, Eun Mi works as a physical therapist while twenty-nine-year-old Jin Hee works as an officer at the Namchon Police Substation. Despite being an adult herself, Jin Hee still lives with her mother; a fact which leads to an endless stream of bickering between the two. Though both mother and daughter will agree that they love each other dearly, the two just can’t seem to find a way to get along these days. As if struggling to find a way to deal with her daughter wasn’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 work’s new director, Eun Jae Won.