On the day when singer Yoo Yeol first became a radio host in 1994, Mi-su (Kim Go-eun), who runs the bakery left by her mother, met Hyun-woo (Jung Hae-in) who appeared by chance. Although they had a heartbeat for each other, they lost contact due to an accident. It was not until three years later that the two miraculously met again. Along with the radio program "Yoo Yeol's Music Book", Mi-su and Hyun-woo searched for the same frequency in various coincidences and inevitability.