• A male professor of Hepato-Biliary-Pancreatic Surgery at Yulje Hospital. • He is funny, witty, and quick-witted, always brightening the hospital atmosphere. • He is in a mutual 'some' relationship with Chae Song-hwa, though neither of them realizes it yet. • He jokes around often and is kind to nurses, residents, and specialists.

• A female professor of Neurosurgery at Yulje Hospital. • She has short hair and wears glasses. • She is in a mutual 'some' relationship with Lee Ik-jun, though neither realizes it. • She is meticulous when treating patients. • She eats a massive amount, earning her the nickname "Muk-kkaebi (Eating Goblin) 1."

• A male professor of Obstetrics and Gynecology at Yulje Hospital. • He has a bear-like personality. • He is more timid than his juniors, but he is incredibly attentive when caring for expectant mothers. • When he is with the 99ers, he becomes more talkative and comfortable.

• A male professor of Pediatric Surgery at Yulje Hospital. • Perhaps because he works with children, he is gentle and kind. • His baptismal name is "Andrea," but due to his peaceful and benevolent nature, he is also nicknamed "Buddha." • His juniors adore him, and he loves children and the hospital staff dearly.

• A male professor of Cardiothoracic Surgery at Yulje Hospital. • He can be blunt and hits people with hard truths. • He jokes around a lot when he's with the 99ers. • He's often on his phone, but he is more sincere than anyone when it comes to his patients. • (Correction) Kim Jun-wan does not use profanity, nor is he rude or thoughtless. He never slacks off with patients; he doesn't try to be funny, but every word he says ends up being hilarious.