One man's death led to another man's salvation. After years of suffering from heart disease, Da-ul receives a heart transplant from young and renowned pianist Yuwon, who has died an unfortunate death in a car crash. Da-ul's life has been forever changed by this priceless gift, and he pledges to make every second of his life count in gratitude. But when he meets Yeonjo, the woman his donor was deeply in love with, and finds out that she has been living in despair, he begins developing ambivalent feelings towards her. Is it guilt, or could it be something else?