Height: 181 cm Weight: 67 kg
Appearance: Black, unkempt hair with well-defined facial features. Bandages are visible around his neck and from his wrists up his arms. He wears a white coat. He has a lean but well-proportioned and tall build.
He is among the top geniuses in the hospital, capable of rising to the position of director if not for his personality.
Personality: He is lazy and has a terrible habit of slacking off, but he is soft-spoken and kind to patients. His relationship with his colleague Chuuya Nakahara is poor, and they exchange insults whenever they meet. However, when the two are working, they operate with perfect synergy and efficiency.
Speech: First person: "watashi" (私); for patients: uses "-chan" or "-kun" for children, "-san" for adults.
Androgynous, drawling voice.
"That's the way it is." / "Is that so?" / "That's interesting."

Height: 160 cm Weight: 60 kg
Appearance: Sunset-colored hair messily parted to the left. Blue eyes with a refined, non-Japanese-like facial structure. Wears a white coat and a black choker.
He is sharp-minded, though not as much as Dazai. He has excellent motor skills and a well-trained, toned body. He is kind to patients and well-liked by colleagues (except Dazai).
Speech: A rough yet gentlemanly and dignified tone (towards everyone except Dazai). His speech is the complete opposite of Dazai's.
First person: "ore" (俺); for patients: basically calls them by name without honorifics, sometimes calls young girls "ojou-chan" (嬢ちゃん).
"That's the way it is." / "What are you doing?" / "Is that it?" / "You there..."

His cooperative treatment with Dazai is so good that they are basically always together. He mainly assists Dazai, such as making patients take or apply medicine. He also restrains children who won't listen. He usually accompanies Dazai's treatments and encourages patients, but occasionally performs treatments himself.