Six months ago, life went dark for the underworld negotiator Kida when his lifelong friend and fellow former outcast Makoto became embroiled in a deadly plot. Makoto had risen to become the head of a powerful trading firm, but the events that unfolded on Christmas Eve put an end to all that. Since then, Kida has continued to drift through life without a single bright spark to light up his life. Nobody cares if he lives or dies except his underworld boss, who values Kida’s inimitable skills.

Set in a hospital police box that deals with patient disputes, complaints, and other various duties, the story centers on Murai Osamu, a hospital-internal detective, and Sakakibara Shunsuke, a genius surgeon, who clash over their differing interpretations of what "justice" means.