Bong Dal Hee (Lee Yo Won) is a first-year resident doctor who strives to become a surgeon despite her heart problem. She works under Dr. Ahn Jong Geun (Lee Bum Soo), a cardiac specialist, and even though they don't get off to a good start, the two grow fond of each other as time goes by. Dr. Lee Geon Wook (Kim Min Joon) divorced his wife, Dr. Jo Moon Kyung (Oh Yoon Ah) after he found out that his 6-year-old son was actually fathered by another man before they married. He still has feelings for her but feels betrayed and cheated. This medical drama portrays the lives of resident doctors, their ups and downs, depicting crisis in a hospital as well as politics among its management staff.