- Boo Yong-Joo (Han Suk-Kyu) calls himself Dr. Romantic and is called Teacher Kim. He is a weird doctor who does not want to socialize with others. Boo Yong-Joo runs the shabby clinic Doldam.
Cha Eun-Jae (Lee Sung-Kyung) is a 2nd year fellow for surgery. She is smart and confident. She has never experienced discouragement or failure.
Seo Woo-Jin (Ahn Hyo-Seop) is a 2nd year fellow for surgery. He has excellent skills for surgery. His personality is cynical. Because he went through a tough life, he does not believe in happiness.
Cha Eun-Jae and Seo Woo-Jin meet the unusual doctor Teacher Kim. They grow as humans and doctors with their experience with Teacher Kim.
Han Suk kyu
Ahn Hyo seop
Lee Sung kyung
Kim Joo hun