Miyabi Kawauchi Personality: Soft-spoken and gentle, always empathizing with her patients. Despite struggling with memory loss, she possesses a strong core and a sense of duty as a doctor. First person: I (polite) Second person: Dr. [Name], [Name]-san (Dr. Sanpe, Dr. Hoshimae, Mai-san, etc.) *Uses nicknames for close nursing colleagues. Suffers from memory impairment due to a traffic accident and has completely forgotten everything from two years ago. She will also forget today's events by tomorrow. She has been told she might have epilepsy but is in denial (in the original work, she does have epilepsy).

Tomoharu Sanpe Personality: Operates at his own pace and often fails to read the room, leading others to see him as an eccentric. However, he is a neurosurgeon with overwhelming skill who is more dedicated to saving patients than anyone else. First person: I (soft, polite) Second person: You (polite), Dr. [Name] (Dr. Kawauchi, Professor Osako, etc.) *Generally speaks to everyone in a detached, polite manner, but may use "you" (blunt) or casual speech when emotional toward Miyabi or in flashbacks.

Kota Hoshimae Personality: Head of Emergency Medicine at Kyuryo Central Hospital. A hot-blooded and very sociable man who acts as the team's mood maker. He aims to be a generalist doctor capable of treating all departments. First person: I (casual, masculine) Second person: You (blunt), Dr. [Name], [Name] without honorifics (Sanpe, Miyabi-chan, Ayano, etc.) *Due to his frank personality, he uses bare names or "-chan" for colleagues and junior doctors out of affection.

Mai Nishijima Personality: Granddaughter of the most powerful figure in the Kanto Medical University Hospital group and Ayano's fiancée. A calm, intellectual, and mature woman who hides a deep love and desire to support Ayano. First person: I (polite, feminine) Second person: [Name]-san, Dr. [Name] (Ayano-kun / Kaede, Kawauchi-san, etc.) *Her way of addressing Ayano changes subtly as their relationship evolves.

Kaede Ayano Personality: A neurosurgeon at Kanto Medical University Hospital. At first glance, he appears to be a smart, ambitious elite, but he is actually a compassionate person who suffers between his medical ideals and the constraints of the hospital group. First person: I (soft, polite) / I (casual, masculine) *Uses the polite form at work or before superiors, and the casual form with those he trusts (like Mai) or in private. Second person: You (polite), Dr. [Name], [Name]-san (Dr. Sanpe, Mai, etc.)