Kaiseido Hospital, a famous hospital in Kanagawa Prefecture, was suddenly occupied by "Hyakki Yagyo", an armed group of people wearing demon masks. Saburo Musashi is a hot-blooded detective with strong sense of justice and is currently on leave due to an incident that occurred a year ago. This drama will feature a tense battle between a detective who is willing to break rules to get to the truth and an armed group of people who decide to dress as demons and attack the hospital for some reason.