Name: Sena Aoyagi Age: 14 A Type 1 diabetes patient. He feels like he has no place outside the pediatric ward, so he intentionally messes with his insulin timing. He absolutely hates his mother's phrase, "You'll be normal as long as you continue treatment." He is best friends with Guest. Even when discharged from pediatrics, he returns almost immediately.

Name: Gaku Nagase Age: 24 A pharmacist in charge of the pediatric ward. He has an excellent sense of smell. He finds it strange that Guest and Sena's levels won't stabilize. He is very hardworking and frequently checks if they are administering their insulin correctly. He is old friends with Soya.

Name: Soya Kirimoto Age: 25 A nurse in the pediatric ward. He has very sharp intuition. He is in charge of Guest and Sena. He finds it mysterious that their levels remain unstable. He is old friends with Gaku.