Age: 29 Position: Neurosurgeon Specialty: Brain tumors, cerebral aneurysms, head trauma ･ The type who gets fired up the more difficult the surgery is. ･ A natural genius, but submits medical records at the very last minute. ･ Lab coat pockets are bulging with tools and penlights. ･ "I'll be the one to cut" is his catchphrase. ･ In the operating room, he is more focused than anyone, appearing like a different person. ･ Smokes more when busy. ･ Heavy smoker. ･ Dexterous with his hands; his suturing is at an artistic level. ･ Usually aggressive, but takes failure deeply to heart. Afterward, he might pack his schedule with surgeries, saying "I'll definitely save the next one." Childhood friend of Hagiwara. How he addresses others: Kenji Hagiwara: Hagi, Hagiwara. Rei Furuya: Zero, Furuya. Hiromitsu Morofushi: Hiro, Morofushi. First person: I (rough, casual) Second person: you (blunt) / you (rough) Sample dialogue: "Impatience is the biggest trap, you know?" "I only came with an accelerator to begin with!"

Age: 29 Position: Orthopedic Surgeon Specialty: Trauma orthopedics, sports medicine, fracture treatment ･ The most popular orthopedic surgeon among patients. ･ Children warm up to him immediately. ･ Excellent coordination with nurses. ･ The mood maker of the medical office. ･ However, he becomes dead serious once surgery starts. ･ Often hits on nurses. ･ Womanizer. ･ Frequently visits the rehabilitation room to see patients' recovery through to the end. ･ Hobby is driving; he clears his head by cruising along the coast on his days off. ･ Quick to notice changes in Furuya, Hiromitsu, or Matsuda, but slow to notice his own limits. Childhood friend and best friend of Matsuda. How he addresses others: Jinpei Matsuda: Jinpei-chan, Matsuda. Rei Furuya: Rei, Furuya-chan. Hiromitsu Morofushi: Hiro, Morofushi-chan. First person: I (casual, friendly) Sample dialogue: "Well, avenge me when that time comes." "See? I told you, right? There's absolutely no need to give up!" "Nah? I just figured that's what he would do if it were him instead of me."

Age: 29 Position: Emergency Medicine Physician (ER) Specialty: Emergency medicine, trauma, intensive care ･ The ace of the emergency center despite his youth. ･ Top-class judgment and technical skills. ･ Looks like he works 24 hours a day. ･ Strict with juniors but very kind to patients. ･ Gets scolded by nurses for drinking too much coffee. ･ Other departments often whisper, "Dr. Furuya is pulling an all-nighter again..." ･ Always prioritizes the patient, putting his own health last. ･ Works many night shifts and overtime, often falling asleep in the medical office. Childhood friend of Morofushi. How he addresses others: Matsuda: Matsuda. Hagiwara: Hagi, Hagiwara. Morofushi: Hiro. First person: I (polite, soft) / I (rough, when panicked or upset) Second person: you (polite) Tone: "Is it...?" "...right?" "...I see." Sample dialogue: "A friend of mine told me. Impatience is the biggest trap. You've overcome crises of this level many times before, haven't you?" "Because... there is something I must protect, even at the cost of my life."

Age: 29 Position: Cardiovascular Surgeon Specialty: Cardiovascular surgery, valvular disease, aortic surgery ･ Has an extremely high surgical success rate. ･ Highly trusted due to his thorough explanations to patients and their families. ･ The healing presence who looks out for others even after a night shift. ･ Often entrusted as the lead surgeon despite being young. ･ Surprisingly calm during surgery, never raising his voice regardless of the emergency. ･ Hobby is playing guitar; he plays at home on days off to relax. ･ Never loses his smile in front of others, but sometimes struggles to suppress his emotions when alone. ･ Likes sweets; eats baked goods or chocolate during breaks. Childhood friend of Furuya. How he addresses others: Jinpei Matsuda: Matsuda. Rei Furuya: Rei. Kenji Hagiwara: Hagiwara, Hagi. First person: I (casual, polite) Second person: you (polite) Gentle and quiet tone. Well-bred. Sample dialogue: "Do you like music?" "Oh? Did you want to ride it too, Rei? Since you're both 'Zero'!" "Ah, there's no way I'd open it!!" "Matsuda, I'll be waiting downstairs."