“I don't do that.” “I also don't fail.” A genius surgeon hiding a dark past. A triple-board specialist in GS, CS, and NS, she possesses overwhelming surgical speed and sophisticated hand skills. She refuses any duties outside her contract, such as rounds, dinners, or assisting with papers. She strictly adheres to a 12 PM lunch and 6 PM clock-out, demanding extra pay for any overtime. Though indifferent and cold, she is more tenacious than anyone when in front of a patient. She likes sweet food and baseball. ⸻ Name: Gye Sujeong / Female / 38 years old Appearance: Long black hair, sharp eyes, white coat. Personality: Cold-headed, caustic, confident, perfectionist. Nickname: The Mad Gye of the OR, Doctor X.

General Surgery Intern A warm-hearted rookie doctor who is quick to notice the sadness of others. He laughs and cries easily and admires Gye Sujeong. Behind his bright appearance, he harbors secrets and wounds, growing as a doctor through her guidance. ⸻ Name: Park Taegyeong / Male / Early 20s. Appearance: Neat black hair, kind eyes, white coat. Personality: Kind, pure, emotional, diligent.

Professor of General Surgery A professor who has compensated for his lack of surgical skill through research and effort. He follows Bu Seungkwon as his mentor and dreams of becoming the hospital director. He values organizational order and feels wary and inferior toward Gye Sujeong's genius. ⸻ Name: Do Yunsik / Male / Mid-30s Appearance: Neat hair, calm impression, coat. Personality: Diligent, calculating, ambitious, cautious. Nickname: The Surgery Sycophant Trio.

Professor of General Surgery and Neurosurgery A laparoscopic expert with dual board certifications. He loves being recognized for his abilities, and his emotions show easily on his face. Usually full of bluster and jokes, he is dead serious during surgery. He values hospital hierarchy and gets angry at Gye Sujeong's attitude, yet feels curious about her skills. ⸻ Name: Bae Heunggon / Male / Early 40s Appearance: Side-parted short black hair, rugged impression. Personality: Hot-tempered, boastful, competitive, loyal. Nickname: God of Laparoscopy, Fire Heunggon, The Surgery Sycophant Trio.

Senior Resident of General Surgery He chose surgery hoping for a stable professorship, but after experiencing operations, he begins to dream of being a real surgeon. While walking on eggshells around his seniors, he agonizes over his career path and convictions. ⸻ Name: Ma Seonggyu / Male / Early 30s Appearance: Short hair, tired eyes, coat. Personality: Realistic, timid, quick-witted. Nickname: The Surgery Sycophant Trio.

Professor of Anesthesiology A cynical truth-bomber who only smiles with her lips. She has excellent observation and judgment, remaining calm in the operating room. She recognizes Gye Sujeong's skills and cooperates with her, but never holds back her blunt remarks. ⸻ Name: Jo Wonjin / Female / Late 20s Appearance: Neat hair, sharp eyes, coat. Personality: Direct, cynical, calm, delicate. Nickname: Smiling Bitch, No-fun Wonjin.

Director of Seonam Hospital Once a pure-hearted doctor, he is now a strategist who compromised with power to protect the hospital. Despite making cold choices repeatedly, he hasn't completely abandoned his past convictions. He is entangled in a complex web of interests with Gye Sujeong. ⸻ Name: Bu Seungkwon / Male / Early 50s Appearance: Neat short hair, dignified impression, suit. Personality: Cold-headed, realistic, strategic, responsible.

“She seemed like a god? Or maybe a monster?” Newly Appointed Professor of Surgery A surgeon who gained the trust of his colleagues through heroic stories from his time as a military doctor. He adapts quickly to the hospital with a kind and sly attitude toward everyone. He is intrigued by Gye Sujeong's genius surgical skills and approaches her actively. However, behind his soft smile lies a dangerous nature and hidden motives. He is skilled at subtly testing people while observing their reactions. ⸻ Name: Na Daeil / Male / Mid-20s Appearance: Neat black hair, glasses, soft smile. Personality: Sociable, sly, cunning, two-faced.

Director of Medical Staffing Agency A sly negotiator with an incredible nose for money. On the surface, she looks like a snob who only cares about cash, but she has excellent wit and judgment, and is capable of handling crises. She manages Gye Sujeong's contracts and fees, taking care of the cleanup. Though she bickers with Sujeong, they are close like aunt and niece. She cherishes and protects her more than anyone else. ⸻ Name: Jang Huishuk / Female / Late 40s Appearance: Short black hair, friendly impression, flashy casual clothes. Personality: Sly, clever, realistic, affectionate.