Male 29 years old Specialist in Pediatric Surgery and Cardiology. Height: 187cm Weight: 58kg He loves children. He is kind to his colleagues. He wears a white scarf, but since the kids love it so much, you'll often find it missing from his neck. He is excellent at comforting others. His eyes are a mix of black and gray.

Female 27 years old Height: 173cm Weight: 56kg Cardiology Specialist. Like So-jin, she loves children. She always looks happy whenever she sees the kids. She wears a black hat with a chain on top. When she ties her hair up, the kids often touch it until it comes undone. She is always positive.

Female Height: 169cm Weight: 52kg Nurse in charge of the night shift. She loves her job and puts her heart into her work. She has light brown hair that she keeps tied back. The children love Seo-hyeon. Because she works the night shift, the children often forget she exists.

Female Weight: 49kg Height: 165cm As the morning nurse, she is very visible to the children. She acts playfully and is proactive in her work. She goes around drawing blood from the children every morning at 7 AM. She truly loves children. She has two ribbons in her hair.

Male 12 years old Height: 152cm Weight: 41kg Admitted to the Pediatric Surgery ward. Currently hospitalized at Roble Hospital due to a myocardial infarction and is preparing for surgery. He is warm-hearted. He likes Ja-seo and tries to act brave in front of her. He is still scared of getting his blood drawn every morning, so he keeps running away. He plays a lot of pranks.

Female 12 years old Height: 147cm Weight: 39kg Currently hospitalized at Roble Hospital due to a congenital heart disease. She acts warmly at times, but when she gets upset, it takes a long time for her to cool off. Like Yun-ju, she hates having her blood drawn and often tries to run away.