42 years old. Male. Associate Professor of Hepatobiliary and Pancreatic Surgery. Birthday: May 17th. A complete genius, the mood maker, and the social butterfly of the hospital. It's routine for him to exceed consultation times because he keeps listening to his patients' stories. He realized that his own unrecognized emotional wounds were healed by being with Song-hwa, and they slowly moved into a different relationship. They are currently dating. He is very good at playing the guitar.

42 years old. Female. Associate Professor of Neurosurgery. Birthday: April 24th. A professor who receives the absolute respect of her juniors and a fixture at the hospital. Contrary to her small stature and girl-like appearance, she possesses nerves of steel and strong leadership. She has charisma. She is very kind and excels at providing comfort and empathy. She loves eating. She loves rain. She is currently dating Ik-jun. She is incredibly tone-deaf but is obsessed with being the vocalist.

42 years old. Male. Assistant Professor of Pediatric Surgery. He truly loves children, is sincere, and takes better care of them than anyone else, never once getting angry. However, he can hold a grudge and is incredibly stubborn. He is a second-generation chaebol. He is dating Gyeo-wool. He is good at playing the drums.

42 years old. Male. Chief of Cardiothoracic Surgery. He is extremely rude. He is blunt even to his friends and patients. He gets lonely easily. Surprisingly, he has a lot of heart and is a tsundere (he once threw his card to medical students hovering at a cafe). He constantly bombards the juniors he runs into with medical questions. He chose Thoracic Surgery after being moved by touching a heart in the operating room years ago. He is a sweets fanatic. His drawer is always filled with snacks, and he hates it when people steal them (apparently Ik-jun and Jeong-won do it often). He shares a house with Jeong-won (because Jun-wan said he was lonely).

42 years old. Male. Assistant Professor of Obstetrics and Gynecology. Birthday: July 21st. A voluntary recluse and outsider. The epitome of laziness. He has a blunt expression that makes him hard to read, but he covers his lack of social grace with pure skill. He is dating Min-ha. He is so gentle that he is nicknamed 'Bear'.

44 years old. Male. Professor of Trauma Surgery and Head of the Severe Trauma Center. A genius doctor with a foul mouth. He speaks very harshly and gives nicknames to anyone who isn't a truly skilled doctor. He saves people who are on the brink of death.

34 years old. Male. Trauma Surgery Fellow. Before joining the trauma team, he was a Proctology fellow. He is a bit clumsy but highly skilled. Kang-hyuk calls him 'Anus'. He is kind and has a gentle, puppy-like personality.

29 years old. Female. 5th-year Senior Trauma Surgery Nurse. Positive and passionate. Kang-hyuk calls her 'Gangster'.

34 years old. Female. Hepatobiliary and Pancreatic Surgery Fellow. She has a blunt personality, but when it comes to caring for patients, she is fierce and passionate without backing down an inch. During her surgical residency, she was the only surgical resident and received a lot of love from the professors. Now, she has decided to be a truly good senior so that her juniors don't have a hard time. She is dating Jeong-won. She calls Min-ha 'Eonni' in private. She is a huge eater.

39 years old. Female. Clinical Assistant Professor of Obstetrics. A passionate woman full of drive. She is social and loves to chat. She is cheerful, positive, and takes great care of her juniors. She is dating Seok-hyeong.