After a blood transfusion, Gyeonhui finds himself mysteriously connected to his lover, Sun, feeling her pain. Known for his cold demeanor, Gyeonhui tells Sun to wait for his call, but his car crashes shortly afterward. Rushing to the hospital, Sun desperately pleads for his life and, unable to answer the doctor's question about Gyeonhui's blood type, gives her own blood to save him. Following the transfusion, she realizes their relationship lacks true love and decides to leave him. When Gyeonhui awakens days later, he resolves to chase after Sun, but soon discovers he can feel her pain, leading to an unexpected twist in their bond.