Yeon Hee works as a director for an English Language Institute. She lives a wealthy life, but after her husband passed away, her only treasure is her daughter Ye Eun. Yeon Hee soon falls into despair when she learns her daughter has heart disease. After going through so much, Yeon Hee pays an exorbitant amount to a black-market organ dealer for a healthy heart for her daughter. The heart comes from a patient in a persistent vegetative state. When the time nears for her daughter's heart transplant surgery, Lee Hee Do, the son of the woman in the vegetative state, suddenly appears to stop the transplant. In the past, Hee Do was a bad son often leeching money off of his mother. He parted ways with his mother, but when he learns of the current situation he tries to protect his mother. With only one heart, Yeon Hee and Hee Do both are both desperate to do what they believe is the right thing.