Growing up as an orphan, ML, Jeong He-Jin didn't open his heart to anyone, and after giving his all to become a cardiothoracic surgeon, he died. When he woke up he realized he was in the body of his Choi GiSeok, the patient that received his heart. After he contemplated what to do, he decided to follow his original dream and become the Greatest Cardiothoracic Surgeon.
Level-Up Doctor (Manhwa)