In the port city of Yokohama , where violent crime is rampant, the head of the Criminal Investigation Department of the Kanagawa Prefectural Police Headquarters, troubled by the declining arrest rate, established a special section called the "Mobile Investigation Unit " that has the power to intervene in all cases occurring in the prefecture and deals with cases that cannot be resolved by investigations at the local level through completely separate operations. The group consists of only five detectives who have deviated from the police organization, and they will be immediately disbanded if they do not achieve an increased arrest rate. Although they are shunned by local detectives, they continue to fight criminals alone and without support.