The Yamaguchi-gumi, Japan’s largest yakuza group, had about 6,000 members at the end of 2015, down 40 percent from a year ago, the National Police Agency said in a report Thursday.
The Kobe Yamaguchi-gumi, a new group born from the breakup of the main group last August, had about 2,800 members, making it the third-largest underworld group after the Tokyo-based Sumiyoshi-kai, the report said.
Yamaguchi-gumi, based in Kobe, and Kobe Yamaguchi-gumi, based in nearby Awaji, are increasing efforts to weaken each other, a senior NPA official said.
Although the two groups have yet to enter a full-blown war, police are stepping up surveillance in view of the many altercations and incidents involving their members nationwide, the official noted.
The NPA survey also found the new yakuza group claims 22 subgroup leaders, with its influence spreading to 36 of the 47 prefectures.
Yamaguchi-gumi retains influence in 44 prefectures, but its subgroup leaders have fallen to 56 from 73 before the breakup.
Yamaguchi-gumi members now make up 29.9 percent of all yakuza in the nation, down from 46.2 percent.
As some members chose to go straight as a result of the breakup, the combined membership of the two groups dropped by some 1,500 to around 8,800.
The combined figure shows that Yamaguchi-gumi’s roster has nearly halved since the end of 2010, with the drop accelerated by local enforcement of a new ordinance for breaking corporate ties with yakuza. The anti-yakuza ordinances had taken effect in all 47 prefectures by October 2011.
The senior NPA official said the drop can be credited to improved efforts by police and anti-yakuza campaigns and the group’s aging membership.
At the end of last year, the there were some 20,100 yakuza, down about 2,200 from the previous year.
About 70 percent belonged to the top four groups, with the Sumiyoshi-kai accounting for around 3,200 and the Inagawa-kai, also based in Tokyo, accounting for about 2,700.
The NPA report also said the Kitakyushu-based Kudo-kai, whose senior members have been arrested one after another on murder and other charges, saw 49 members exit, marking its biggest annual loss.
This reduced its roster to about 470.