Dr. Nagao graduated from the Faculty of Medicine at Shinshu University in 2007, obtaining his medical license. He completed his initial clinical training at Tokyo Metropolitan Bokutoh Hospital, rotating through various departments, and later pursued advanced surgical training as a senior resident at Yokohama City Minato Red Cross Hospital. He then worked as a staff physician at the Advanced Critical Care and Emergency Center of Tokyo Metropolitan Bokutoh Hospital, focusing on emergency medicine, intensive care, trauma, and burn care.

Since 2015, Dr. Nagao has expanded his expertise globally, participating in short-term clinical fellowships in Acute Care Surgery and trauma surgery in Finland, Thailand, and South Africa. In 2016, he joined the Department of Emergency Medicine at Teikyo University School of Medicine as an assistant professor, engaging in emergency care, trauma surgery, and medical education.

In 2022, he was appointed assistant professor in the Department of Surgery at Teikyo University, contributing to the establishment of the Acute Care Surgery division. In 2024, he became a lecturer in the Department of Emergency Medicine, continuing his work in clinical care and education. He is currently a staff physician at the Advanced Critical Care and Emergency Center of Tokyo Metropolitan Bokutoh Hospital and serves as a part-time lecturer at Teikyo University School of Medicine, actively involved in teaching emergency medicine.

Dr. Nagao holds several certifications, including Specialist in Surgery from the Japan Surgical Society (2013), Specialist in Emergency Medicine from the Japanese Association for Acute Medicine (2016), Certified Surgeon in Acute Care Surgery from the Japanese Association for Acute Care Surgery (2020), and Specialist in Trauma from the Japan Society of Trauma Surgeons (2023). He is an expert in surgery and emergency medicine with extensive clinical and academic experience. Additionally, he has completed the doctoral program at Teikyo University Graduate School of Medicine and is set to earn his Ph.D. in Medicine in 2024.