Police in Japan are bracing for an outbreak of gang violence after reports that the Yamaguchi-gumi – the country’s biggest crime syndicate – is about to split. Japanese media reports said the organisation had been hit by rows over members’ divided loyalties toward the gang’s boss, Shinobu Tsukasa. The 73-year-old, who became Japan’s most powerful mafia don in 2005, has reportedly angered affiliated gangs by giving preferential treatment to certain members and spearheading a push into new territory far from the gang’s traditional turf. Tsukasa, who also goes by the name Kenichi Shinoda, was released from prison in April 2011 after serving a six-year sentence for firearms possession. The Yamaguchi-gumi – whose members account for just under half of Japan’s gangsters – has been called the Wal-Mart of the country’s underworld for its ability to see off opponents and generate huge earnings. According to police sources quoted by the Sankei Shimbun newspaper, more than a dozen gangs with connections to the Yamaguchi-gumi decided to form a breakaway group in protest at the emphasis Tsukasa is placing on the Kodo-kai, a Nagoya-based affiliate he founded in 1984. Under Tsukasa, the Kodo-kai has been expanding its influence in Tokyo and other parts of eastern Japan – a move that has angered members in the Yamaguchi-gumi’s traditional base in western Japan. Police were preparing for a possible outbreak of violence between the new breakaway group and the 20 organisations that remained loyal to Tsukasa, Japanese media said. Law enforcement officials fear a repeat of the bloodshed that followed a similar split in the 1980s, when more than 20 gangsters were killed and hundreds arrested over a five-year period. Police in the western port city of Kobe – the location of Yamaguchi-gumi headquarters – believe the latest round of mutually destructive strife could spark more deadly confrontations. “The police are reportedly very concerned, and are taking measures to pre-empt any problems that might happen this time around,” said Brett Bull, who writes about organised crime for the Tokyo Reporter website. High-ranking members of the dissenting groups reportedly failed to attend a meeting at the Yamaguchi-gumi’s headquarters last week. The break is expected to be formalised at a gathering of senior crime bosses early next month, media reports said. Although their capacity for violence pales alongside that of the mafia and Chinese triads, Japan’s yakuza groups make their money from activities ranging from prostitution to extortion and white-collar crime. Membership of the yakuza is not illegal, but recent police crackdowns and the faltering economy have eaten into gang profits and made membership less attractive than it was during the “bubble” years of the 1980s. “The latest split is more about Japan’s economy rather than the ongoing police crackdown,” Bull said. “Simply put, there is more money to be made in Tokyo, and the Yamaguchi-gumi’s shift in emphasis towards the Kodo-kai and Tokyo has caused frustration among gang members in western Japan.” Yakuza membership fell to an all-time low in 2013, slipping below 60,000 members for the first time, down from about 63,200 in 2012, according to the national police agency. Local governments have introduced laws aimed at shaming legitimate businesses into shunning the mob. Firms that knowingly do business with the yakuza risk having their names made public if they refuse to sever ties with organised crime. Repeat offenders face fines of up to 500,000 yen (HK$32,000), and company officials can face jail terms of up to a year. Faced with depleting returns from traditional sources of income such as gambling and drug smuggling, some gangs have become active in the stock market, through “respectable” front companies. The shift to white-collar crime prompted authorities in the US to freeze the Yamaguchi-gumi’s assets after evidence emerged of a lucrative international operation that included weapons trafficking, prostitution, human trafficking and money laundering.