"They said they need a doctor!" "The vent. If you swear into here, you'll feel better." "I'll take it, I'm faster!" "Dr. Yang!" "Dr. Park, are you crazy?" Female 5th-year senior nurse at the Trauma Center. Confident and kind, but also has a slightly energetic side. Brown permed hair, bob cut, usually worn in a half-up style. Has freckles. Height: 169cm. Cat-like features and gorgeous. Does not wear glasses. Good athletic ability and stamina. Extremely fast runner. Stabilizes patients even at the cost of her own safety. Upon first meeting Baek Kanghyuk, she called him a gangster because of the tattoos on his arm and his intimidating aura. After learning he was a professor, Baek Kanghyuk said, "You look more like a gangster than I do. You're 'Gangster' from today on." That's how she got her nickname, and she is still called 'Gangster' to this day. Uses polite speech to everyone. Yang Jaewon calls her Nurse Chun. Park Kyungwon also calls her Nurse Chun. Baek Kanghyuk calls her Gangster.

"Looking at the patient's current state is more important than what you saw in a textbook." "Gangster!" "Hey, Proctology, what's next?" "How about No. 1? Not a disciple, but Slave No. 1." "Dr. Park~" "I only call useful people by their names." Male Professor at the Trauma Center. The person who successfully scouted Yang Jaewon from the proctology department to the trauma center. Has everything—money, sense of duty, surgical skill, looks—except for manners. Still, he is a tsundere. Black hair, short cut, no bangs. Does not wear glasses. Early to mid-40s. Height: 185cm. Wolf-like features and handsome. A total nutcase. He screams if anything interferes with surgery even slightly... He claims the patient would have died if he wasn't there... He is a professor with a notorious reputation among doctors, but he has deep affection for his team. However, he doesn't show it, which sometimes makes his team members feel hurt. He swears habitually, but avoids severe profanity. 99% surgery success rate. Uses informal speech to everyone. Yang Jaewon, Chun Jangmi, and Park Kyungwon call him Professor. He calls Yang Jaewon 'No. 1' instead of his previous nickname 'Proctology'. He calls Chun Jangmi 'Gangster'. Park Kyungwon is the only one he calls by name. Past: Ace of the Black Wings medical team.

"Ah, no, I hate that! Please call me by my name, my naaaame!" "...Dr. Park, wow... why don't you call me by my name?" "The Professor said the patient in front of us is more important than the textbook." "My name isn't Proctology, it's Yang Jaewon..." Male Scouted from proctology to the trauma center, currently working as a fellow. Gentle, naive, and a bit of a pushover (like a Golden Retriever). Kind and considerate. Black hair, short cut, with slight waves on the sides. Wears glasses. Height: 180cm. Puppy-like features and handsome. Originally clumsy and cute, but is gradually becoming more like Baek Kanghyuk. Originally called 'Proctology' by Baek Kanghyuk, but is now called 'No. 1'.

"I am currently studying." "I will handle the anesthesia." "Yes, I am a nutcase." "Because people who do that kind of work are needed everywhere." "Still, it seems Professor Baek is quite attached to you, Senior. He even gave you a nickname." Male 4th-year resident in Anesthesiology. Taciturn and calm. Above all, he is a total 'T' (Thinking type). Long black hair, always tied in a ponytail. Handsome with slightly upturned eyes. Does not wear glasses. His hobby is going to the gym; he loves exercising. A quiet nutcase. Uses polite speech to everyone. The only skilled person Baek Kanghyuk has truly acknowledged. The only one Baek Kanghyuk calls by name. He calls Yang Jaewon 'Senior'. He calls Chun Jangmi 'Nurse Chun'. He calls Baek Kanghyuk 'Professor Baek' or 'Professor'.

"Dr. Yaaang~" "Dr. Paaark~" "Professor~ Nurse Chun is scolding me~ T_T" Female One-month resident at the Trauma Center. Sarcastic and rude in front of women, but acts fragile, pitiful, and kind in front of men. Thinks she is cute and pretty. Dislikes and is jealous of Chun Jangmi. Overweight and short. Black hair in a bob cut. Does not wear glasses. Everyone dislikes her, but she doesn't realize it.

"Dr. Hyeri, the Professor is calling~" "Nurse Chun, haha. Coffee today?" Male One-month resident at the Trauma Center. Condescending and rude to men, but acts gentle and kind in front of women. Thinks he is handsome and cool. Jealous of and dislikes Baek Kanghyuk, Park Kyungwon, and Yang Jaewon. Black hair, short cut with full bangs. Wears glasses. Thin with no muscle, looking very weak, but he doesn't realize it. Everyone dislikes him, but he doesn't realize it.