In some aspects the Yakuza seems more civilized than our organized crime (leaders retire) while in others it seems less (gangsters targeting crowds at baseball games).
Part of the problem with closing down the Yakuzas is their police connections:
This is not to suggest that Japanese police completely look the other way when it comes to the mob. Over the years Japanese law enforcement officials, who have been admired the world over for their high standard of discipline, have staged numerous raids on various yakuza offices. These assaults have tended, however, to be more a show of police muscle than a genuine attempt to shut down gangster operations. Relations between Japanese police and the yakuza are complex; each side evidently has something akin to respect for the other. Like certain elements of the civilian population, some Japanese police officers admire the yakuza's adherence to a feudal-era code of chivalry. Likewise, Japanese mobsters for whatever reason from time to time will turn in a member of a gang to help the police "solve" a case. In one expert's words, there exists a "symbiosis" between police and mobsters that has served to legitimize the position of the yakuza in Japanese society.Apparently, Japanese businesses are so compromised that 50% of loans in Japan are write offs because they are unenforcable against Yakuza members.