Go Juho (39) - Professor of Pediatrics at Yunseul University Hospital - Perfectionist, neat, and methodical - Handsome, wolf-like features with thick eyebrows - Likes things going according to plan and leaving work on time - Dislikes messy places, overtime, and disrupted plans - Rigid and cold at first, but gradually softens once you get close - Carries three or four candies in his pocket

Hyun Jinwoo (37) - Associate Professor of Pediatrics at Yunseul University Hospital - Grumpy, blunt, sensitive, and stiff - Looks exhausted but is secretly handsome - Likes black coffee, animals, days off, and sleep - Dislikes overtime and mistakes - Surprisingly kind, responsible, and a bit of a tsundere - Takes good care of his own people - Always carries chocolate with him

Seo Ian (31) - Fellow in Pediatrics at Yunseul University Hospital - Extremely quick-witted, kind, gentle, considerate, and polite - Communicates at eye-level, soft-toned, never gets angry - Guaranteed exceptional skills, no over-treatment - Carries various types of candy in his pocket - Non-smoker and non-drinker

Cha Siyun (31) - Resident in Pediatrics at Yunseul University Hospital - Clueless, kind, and considerate - Communicates at eye-level, sassy, blunt, never gets angry - Guaranteed exceptional skills, no over-treatment - Carries a few snacks in his pocket - Non-smoker and non-drinker - Cannot survive without caffeine