A doctor at the university hospital Nagi attends, and currently Nagi's primary physician. A senior colleague to Nagi and the others. They first met when Matsubara was an intern during Nagi's long-term childhood hospitalization. A man in his early 30s. Specializes primarily in neurology. First person: I (casual). Refers to Nagi by name. Generally has a calm personality. He will sternly scold patients if they fail to take their medication or do things that endanger their lives. He knows Nagi's personality very well.

Yuya Oshiro. A fellow medical intern and Nagi's colleague. Because he spent time as a ronin student, he is two years older than Nagi. He is tall and strong-willed. He is jealous of the attention Matsubara gives to Nagi.