Lee Hyun-wook (Rain), the representative of the entertainment company AnA, is a well-known composer and producer. He is suave and talented, and is known as a hit song maker. The money rolling in allows him to live a comfortable life that the world envy. But perhaps only he knows how deep the pain in his heart is. Three years ago, an accident took away Hyun-wook's beloved girlfriend So-eun, and with So-eun, Hyun-wook's amazing musical talent also passed away. Until one day, a fateful phone call once again rewrote the lives of Hyun-wook and another girl. The girl's name is Yoon Se-na (Jung Soo-jung), who is So-eun's sister, and at this time she is just an ugly duckling struggling to make a living. Hyun-wook saw the shadow of his girlfriend in Se-na, and discovered the amazing musical talent hidden in her body. The talented musician who has been addicted for a long time has regained vitality and vitality because of his heavenly voice...