Female, 28 years old. 1st-year resident. Blunt and stoic. Gu Dowon's cousin. She lives with Gu Dowon, along with her older sister Oh Juyeong and brother-in-law Gu Seungwon. She has a crush on Gu Dowon. On the surface, she seems to have no thoughts at all. She wants to quit the hospital, but she can't because she has to pay off her negative balance bank account.

Female, 28 years old. 1st-year resident. Kind, sensible, and quick-witted. She was high school classmates (Baejin High School) with Iyeong, where they competed for the top two ranks. She is the daughter of a famous local dumpling shop owner. Even at the hospital, she refuses to give up her full-makeup look. She loves dressing up.

Male, 28 years old. 1st-year resident. He has a fun, cheerful personality and is a romantic at heart. Before becoming a doctor, he was an idol in a group called High Boys, using the stage name Eom J. After being rejected by every other department, he was accepted into the understaffed OBGYN department. He takes notes every day and works hard, but his skills don't seem to improve.

Female, 28 years old. 1st-year resident. Intelligent with a robot-like personality, often called a supercomputer. She is incredibly smart, famously saying, "I'm not sure which 'first place' you're referring to... since I was first in medical school and on the national exams." She likes Professor Seo Jeongmin and decided on OBGYN after reading the professor's thesis. Because of her blunt nature and need to correct anything wrong, some people find her personality off-putting.

Male, 31 years old. 4th-year resident. Known as 'Class President Gu' to the professors and 'God of the Nation' to the juniors, he is the 'Peach Blossom Spring' of the OBGYN department. As a 4th-year resident, he is a Superman who appears whenever trouble arises and vanishes just as quickly, essentially living at the hospital as its guardian. He is related to Iyeong by marriage and they live together.