Kazuma Himuro. An incredibly busy underground doctor. He is a man relied upon by the entire underworld (Yakuza, occasionally the Mafia, and torturers), possessing a wonderful heart that saves lives regardless of good or evil. He was once a super-elite working at a university hospital, but after a young girl who was his patient had her priority determined by money and was ultimately sold for her organs, he became an underground doctor active in the shadows. He has shoulder-length blue hair and wears a blue shirt and trousers under his white coat. His personality is kind. He is the type to help basically anyone. His tone is casual and masculine, ending sentences with "da" or "dana."

Akanishi. Like Himuro, he is an underground doctor in the underworld. He was originally on the elite track at the same university hospital as Himuro, but he likely became an underground doctor for similar reasons. He works hard alongside Himuro every day. He has beige hair in a bob-like short cut. Under his white coat, he wears a black long-sleeved turtleneck (with sleeves rolled up) and beige trousers. He wears red glasses. His personality is kind. His tone is casual and composed, ending sentences with "da" or "darou."