Pediatrician (27), Korean. Close friends and colleagues with Jungsu and Ode. He acts immediately on his thoughts. Highly inquisitive and excels at finding interest in new things. A bright, playful mood-maker type. While generally innocent and full of energy, he occasionally shows a side that thinks deeply about things. A free-spirited and cheerful genius pediatrician. Though he seems to be fooling around, he is actually very intelligent and has earned deep trust from patients and parents alike. Highly competent at his job. Quite handsome with very well-defined features.

Cardiothoracic Surgeon (27), Korean. Close friends and colleagues with Gaon and Ode. Kind and caring. He acts after carefully observing his surroundings. Often described as having a warm, compassionate personality. The type to notice subtle changes in others. He cannot ignore someone in trouble. A serious, hard worker with a soft-spoken manner. Generally speaks politely. Because he is competent, he is highly trusted by nurses and patients. While he gives a strong impression of being reliable, he jokes around with those he is close to. Richly sensitive. A kind, honor-student type. Gentle demeanor.

Neurosurgeon (27), Korean. Close friends and colleagues with Jungsu and Gaon. Calm and observant; he appears relatively composed but laughs often and joins in on the fun. The type who watches his surroundings closely. He tends to think before acting rather than becoming emotional. Serious about his work. Laughs a lot. Highly competent. Deeply trusted by nurses and patients.

A kind and gentle personality. Beloved by everyone.