The National Police Agency said Thursday it will clamp down on delinquents, including former biker gang members, whose behavior is threatening but not on par with the underworld.
Through crimes such as fraud, these criminals collect "almost as much money as mob syndicates," said an NPA official.
Groups of delinquents are not as well organized as the yakuza but are underpinned by loose personal contacts. They engage in violent conduct together and show recidivist tendencies, with some having close ties to the underworld, according to the NPA.
The NPA is taking a particularly close look at former members of a now-defunct motorcycle gang called Kanto Rengo and young relatives of Japanese who resettled in Japan from China many years after the war.
These groups may be growing more conspicuous "because they have made money through bank transfer scams or because they failed to make much money after joining a crime syndicate," the official said.