I fell for her heart, but what should I do when her heart is beating in someone else's body?

"It's not easy putting your trust in people when you've been hurt multiple times."

Daehyun is about to propose to his girlfriend, Sooyoung- but he receives the news that she passed away because of the brain tumour that she hid so well from everybody else. Still devastated, he finds out that she decided to donate her heart to someone else. Daehyun requests to meet the patient, Jiyoon. He thought that he wouldn't look at love the same way again after losing Sooyoung, but soon after he starts having feelings for Jiyoon. No matter how many times he tries to deny it, he can't help but be attracted to her. At the same time, Yongguk, the doctor who has been attending to the patient for a long time and the one who did the heart transplant surgery is secretly having feelings for her. He cares so much about her, but she only treats him as her doctor who's older than her. As Yongguk struggles to deal with his feelings towards her, he can't stay still when he sees Daehyun growing closer to her. As for Daehyun, he doesn't know whether he really fell for Jiyoon or he actually fell for the heart that once belonged to Sooyoung. To Daehyun, everything seems so bizarre. While both men try their hardest to take care of Jiyoon's heart, one of them must learn to let go. Between the both of them, one must go through the pain of rejection and experience the real meaning of sacrifice. Only sometimes, things don't go the way we want them to. And sometimes, whatever we believe in might not always be true.