Note: I'd like all the characters to have had some contact with the Yakuza in Angelus as part of their backstory. They could have either positive contact (He saved my life!), negative contact (He mugged me!), or neutral contact (I watched the Yak save a life, then mug someone!). It can be either with the prior regime (reserved and low-key, white collar crime) or the new and current regime (aggressive and involved with the supernatural)
After 2113, Angelus prospered. After the destruction of the previous year, the city was invigorated by a feeling of pride and ambition. Part of that recovery involved the Kurobara-kai, a powerful Yakuza group headed by the mysterious Hanzo Sattori. Sattori's approach to Angelus was very low-key. The Kurobara-kai spread themselves out over the huge city one sector at a time, providing assistance during the crisis to both refugees and those who stayed behind. Over the next few years, the Kurobara-kai was omnipresent in nearly every level of Angelus society.
Sattori's style of crime was very white-collar in nature. He commanded his men to avoid violence and kept a firm hand on his operations so that the police forces of Angelus were not provoked into an escalating response. There were many times that his calm demeanor and the reputation of the Kurobara-kai defused tense situations, and in return, the Yakuza enjoyed fairly light sentencing when caught and convicted. Which, thanks to Sattori's diligent lawyers, was rare. During Sattori's reign, the Yakuza in Angelus were involved in extortion, embezzlement, bribery, smuggling, corporate crime (stock transactions and sokaiya blackmail), prostitution and sexual slavery.
On the other side of this coin, the Kurobara-kai also provided neighborhood protection. Street gangs were virtually eliminated in Yakuza-controlled areas and more than a few incidents involving Entities or other supernatural threats were exposed and brought to XSWAT's attention through the activities of the Yakuza. Kurobara-kai ships funneled thousands of immigrants into the city, mostly fellow expatriate Japanese and Korean groups seeking new homes and opportunities. Lastly, Sattori was lavish in his public support for charities and employment programs, particularly in Epsilon Sector. Collectively, Sattori's investments provided legitimate jobs for over eight thousand of Angelus's citizens, none of which were members of the Yakuza.
Everything changed in 2118. On Halloween, a massive purge of the Kurobara-kai was conducted in the shadows of Angelus's underworld. More than six hundred bodies were found the next day, murdered by ritual sorcery. Overnight, the Kurobara-kai ceased to exist, conquered in a bloody coup by one of Sattori's lieutenants, a powerful mahatsukai (sorcerer) known only as Ryuzo.
Ryuzo declared that the Yakuza in Angelus would henceforth reclaim the name of the Yamaguchi-gumi. One of the largest and most powerful Yakuza gangs in Japan, the Yamaguchi-gumi declined after the cataclysm and had been considered a footnote for several years prior to this incident. Reborn out of the ashes of that Halloween night, Ryuzo sent his Yamaguchi-gumi out into the city to make Angelus into a gangster's playland.
The Yamaguchi-gumi were cut from quite a different cloth than their predecessors. Aggressive and savage, the Yakuza after 2118 had no concern for anyone other than themselves and honored no limits. Rape, murder, assault and other violent crimes rose phenomenally. Street gangs flourished, often used as pawns by Yamaguchi-gumi underbosses to see whose territory was the strongest. Economists point to the ascension of the Yamaguchi-gumi as one of the key elements in Angelus' depression, as many of the smaller businesses trying to take the place of the megacorporate interests were either intimidated into closing down or had their profits funneled directly into the Yakuza's coffers. Safety for the average citizen is a serious concern in 2123 thanks to the excesses of the Yamaguchi-gumi.
Angelus's Yakuza problem has yet another significant wrinkle. A powerful mahatsukai himself, Ryuzo has recruited many more spellcasters into the ranks of his underbosses. As the Oyabun (leader) of the Yamaguchi-gumi, Ryuzo has encouraged the use of supernatural assets in Yakuza operations city-wide. A restaurant that fails to pay protection money is burned to the ground by green flames. A summoned Entity consumes the bodies after a home invasion. A death curse targets a prominent district attorney. There are even rumors that there are some spirits of ambition and violence that attend Ryuzo or have joined the gumi as underbosses themselves.
Of all the threats facing Angelus, few are as pervasive or as dangerous as the Yamaguchi-gumi themselves. XSWAT has had several clashes with the Yakuza over the last three years, each time increasing in body count and collateral damage. Director Renuka herself has had to disrupt further attempts at ritual sorcery.