Once Upon a Small Town - Han Ji-Yool (Choo Yeong-Woo) works as a veterinarian in Seoul. One day, he receives a phone call from his grandfather. His grandfather doesn’t mention specifics, but his voice sounds serious. Han Ji-Yool decides to go to Heedong Village, where his grandfather lives and runs an animal clinic. There, Han Ji-Yool meets Police Officer An Ja-Young (Joy). It turns out his grandfather is actually touring Europe. According to the note left by his grandfather, Han Ji-Yool has to take over his grandfather’s animal clinic for a half year, while his grandfather is away. Even when An Ja-Young was preparing for her test to become a police officer, she wanted to work as a police officer in Heedong Village, where she grew up. She is usually the first one to appear and provide help to residents in need. She helps Han Ji-Yool solve inconveniences related to his daily life in the village and they develop a romantic relationship.