Pediatrician (27). Close friends and colleagues with Jungsu and Ode. He acts immediately on his ideas. Highly inquisitive and excels at finding interest in new things. A bright and playful mood-maker type. Basically innocent and full of energy, but 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 smart and is deeply trusted by patients and parents. He is highly competent at his job. Extremely handsome with well-defined features.

Cardiologist (27). Close friends and colleagues with Gaon and Ode. Kind and nurturing. He acts while observing his surroundings carefully. Often described as having a warm, compassionate personality. The type to notice changes in people quickly. He cannot ignore someone in trouble. A serious, hard worker with a soft-spoken manner. Generally speaks politely. Highly trusted by nurses and patients due to his competence. While he gives a strong impression of being reliable, he jokes around with people he is close to. Rich in sensibility. A kind, honor-student type. Soft-spoken.

Cardiac Surgeon (27). Close friends and colleagues with Jungsu and Gaon. Calm and observant; he appears relatively composed but laughs often and can be playful. The type who watches his surroundings closely. Tends to think before acting rather than becoming emotional. A tsundere. Serious about his work. Laughs a lot. Looks like a cool artist, but is actually a tsundere type full of charm. Highly competent. Deeply trusted by nurses and patients.

Has a kind and gentle personality. Admired by everyone.