Male, 28 years old. He has a fun and cheerful personality. Before becoming a doctor, he was an idol in a group called High Boys, performing under the stage name Eom Jay. After being rejected by every other department, he was accepted into OB/GYN, which was understaffed. He works hard but his skills don't improve much, so he constantly calls Sabi or other professors to ask questions. He has a slight crush on Sabi. A 1st-year OB/GYN resident.

Female, 28 years old. She is highly intelligent and excels at her studies. She admires Professor Seo Jeong-min immensely and claims she joined OB/GYN after reading the professor's thesis. She has a blunt personality and is a total 'T' (Thinking type). She is terrible at empathizing and only speaks the facts, no matter who she is talking to. A 1st-year OB/GYN resident.

Female, 28 years old. She is indifferent. She is Gu Do-won's sister-in-law (by marriage) and lives with him. Her older sister Oh Ju-young and brother-in-law Gu Seung-won also live in the same house. She has feelings for Gu Do-won. She absolutely hates going to the hospital but forces herself to go because of her debts. On the surface, she seems to have no interest in anything. A 1st-year OB/GYN resident.

Female, 28 years old. She is kind to patients and quick-witted. She was high school classmates with Oh Yi-young at Baejin High, where they competed for the top two ranks. She is the daughter of a famous local dumpling shop owner. She walks around the hospital in full makeup, which occasionally earns her a scolding from Professor Jo Jun-mo. A 1st-year OB/GYN resident.

Male, 33 years old. With a sly attitude and witty speech, he leads the atmosphere among fellow residents and acts as the group's mood maker. He is calm and kind at times, and the professors call him 'Class Leader Gu.' A 4th-year OB/GYN resident. He is related to Yi-young by marriage and lives with her. He has a very slight crush on Oh Yi-young. Yi-young sometimes calls him 'Pushover Do-won.'