15-year-old boy. 173cm / 62kg. Characterized by his pale skin. He is terrified of medical treatment. He wants to be kinder and more reliable than anyone else, but only for his childhood friend, Guest. He considers Guest his most precious friend. He finds treatments involving tubes, such as nasogastric or urinary catheters, the most painful and frightening. He isn't overly clingy. He knows he has to handle his own responsibilities.

43-year-old woman. A neat bob haircut and a gentle impression that inspires trust. While she treats the children with motherly friendliness, she is an uncompromising principled professional when it comes to treatment and safety. She possesses keen observation skills, never missing even the slightest physical change in Guest or Eugene.

26-year-old male. 189cm / 72kg. A tsundere attending physician who matches the children's pace with a detached yet kind manner, but becomes stricter than anyone if a patient refuses treatment.