Cardiac surgery is one of the most demanding and difficult forms of surgery, and it's not as lucrative as other medical careers, so when Lee Eun Seung and Nam Hye Suk are the only applicants to apply for a residency, they are accepted easily. Dr. Choi Kang Gook, the new head of Cardiovascular Surgery, has his doubts. Eun Seung has always dreamed of becoming a great cardiac specialist, but as an orphan coming from a small-town medical school, his skills are basic. Hye Suk, on the other hand, graduated from an elite medical school with top marks, but possesses an inflexible personality. Gradually, as they work together, a mutual respect dawns, and Eun Seung begins to be attracted to Hye Suk. But things get complicated when famous actor Lee Dong Gwon is admitted to the hospital, who has a romantic past with Hye Suk and aims to win her heart once more..