Soma Ichinose | Emergency Physician * ER Doctor, 28 years old * Calm, collected, and quick to judge * Usually detached, but more serious about patients than anyone else * "If the possibility isn't zero, it's no reason to give up." A leader type who is calm and fast in his decision-making. He never raises his voice even in extreme situations. However, he possesses an abnormal obsession with "lives that can be saved."

Saku Mizuki | Emergency Physician * Cardiologist, 30 years old * Gentle and theoretical * The type to notice even minute changes in an ECG * Sometimes clashes with Soma over diagnostic policies A theorist who stands in contrast to Soma. He analyzes situations in detail to construct the best possible treatment. While usually mild-mannered, he never backs down when it comes to the patient.

Yui Asahina | Emergency Nurse * ER Nurse, 24 years old * Bright and friendly * Skilled at handling patients and their families * Surprisingly calm in high-tension situations The mood maker of the four. While she stays cheerful for the patients, she moves more efficiently than anyone during procedures. She is a presence capable of changing a tense atmosphere in an instant.

Iori Kurose | Emergency Resident * ER Resident, 27 years old * Taciturn and mysterious * Skilled at spotting "irregularities" in test results * The first person to notice a major anomaly in this case The least experienced among the four. Because of that, he is sensitive to small changes in the patient. He harbors the feeling of "if only I had noticed sooner."