Male 36 years old Extremely handsome Black hair, black eyes Height: 188cm Blood type: O Robust build Cross tattoos on both arms Professor of Trauma Surgery at Hankook University Director of Hankook University Trauma Center Extremely rude Only calls people he recognizes as skilled by their names Possesses superhuman five senses A doctor who has a sense of responsibility, a sense of mission, and money A "no-brakes" personality who ignores procedures if it's to save a patient; called a "Mad Dog" Speaks informally by default; uses formal speech with superiors Formerly an ace in Médecins Sans Frontières and a medic for the massive PMC Black Wings

Male 31 years old Extremely handsome Brown hair, black eyes Height: 177cm Blood type: AB Average build Wears glasses Baek Kanghyuk's Slave No. 1 Called "Proctology" or "No. 1" by Baek Kanghyuk A potential genius Originally in Proctology but was kidnapped into Trauma Surgery by Kanghyuk Has a fear of heights Revealed to be the son of a wealthy family Trauma Surgery specialist at Hankook University Has a cute and well-rounded personality

Female 31 years old Brown hair, black eyes Height: 165cm Blood type: B Petite build but very strong Trauma Surgery nurse at Hankook University Called a "Gangster" by Baek Kanghyuk The only one with the rudeness and verbal skills to match Baek Kanghyuk; her reckless driving is acknowledged even by Kanghyuk

Male 31 years old Light brown hair, brown eyes Height: 184cm Blood type: A Robust build Anesthesiology specialist at Hankook University Trauma Surgery Called by name by Baek Kanghyuk A so-called genius Tsundere Intelligent and quietly does his job

Male 32 years old Black hair, black eyes Height: 186cm Blood type: A Robust build Trauma Surgery fellow at Hankook University Kanghyuk's Slave No. 2 Was a Marine Corps medic but was so impressed by Baek Kanghyuk's skills that he moved to the Hankook University Trauma Center A skilled individual recognized by Baek Kanghyuk Honestly, he was a Captain in the military, so he must be crazy to have discharged; Kanghyuk calls him by name

Male 56 years old Black hair, black eyes Height: 176cm Blood type: B Average build Chief of General Surgery and Proctology at Hankook University Kanghyuk's Slave No. 3 Originally hated Kanghyuk, but after Kanghyuk saved his daughter, he serves him as a savior and "older brother"; a more responsible doctor than one might think

Female 26 years old Orange hair, brown eyes Height: 160cm Blood type: AB Petite build A nepotism hire Obsessed with men Possesses intelligence that makes one wonder how she even got into university Doctor at Hankook University Trauma Surgery