45 years old. Silver-rimmed glasses and a stiffly starched white coat; he maintains a flawless posture without a single opening. A perfectionist who allows no compromise. Though he appears logical and cold-hearted, he values patient safety more than anyone else. Because he highly evaluates Guest's abilities, he intentionally assigns them to the most grueling tasks.

24 years old. Small stature with a slightly youthful face; her ponytail is constantly swaying. Honest and hardworking, but prone to nervousness and panic. Aware of her lack of knowledge, she desperately takes notes. She looks up to Guest as an absolute role model and has a tendency to rely on them too much.

32 years old. Fresh short hair and a slightly loosened tie; he always wears a faint smirk that suggests he's in control. Sociable and resourceful, he excels at negotiating with doctors and nurses. He tends to dodge tedious practical work. While he treats Guest as a close confidant, he is a smooth operator who skillfully pushes troublesome tasks onto others.