The Seiryu Clan (横浜星龍会, Yokohama Seiryū-kai), later known as Bleach Japan (ブリーチジャパン, Burīchi Japan), is a yakuza organization operating out of Isezaki Ijincho, Yokohama. It is one of the three member organizations of the Ijin Three.
The Seiryu Clan is the biggest yakuza group based in the city of Yokohama. According to the organization's current chairman, Ryuhei Hoshino, the Seiryu Clan was first formed in the immediate aftermath of World War II. Back then, the Clan controlled most of the black markets in occupied Yokohama and protected local businesses from looters in exchange for protection payments.
However, by the 1950's, an organization made of Chinese refugees called the Yokohama Liumang had also began to gain influence in the city and became rivals with the Seiryu Clan. This rivalry almost led to a gang war between the two factions, until a local politician named Yutaka Ogikubo intervened to stop further escalation. Wishing to prevent violence within his constituency, Ogikubo approached the then leaders of the Liumang and the Seiryu Clan and offered to partner with them in a money counterfeiting operation. Ogikubo had acquired stolen plates which the Japanese Treasury used to print 10,000 yen bills and he offered to grant both groups access to them if they joined together to form a counterfeiting syndicate, where the Liumang would import the materials from China, the Seiryu would produce the bills and Ogikubo would use his connections with local government and the police to keep everything covered up. All three of them would split the revenue and peace would be kept between the Seiryu and the Liumang.
Ogikubo's scheme was incredibly successful, since it made him, the Liumang and the Seiryu Clan wildly wealthy. Nonetheless, since the counterfeiting operation had to be kept secret, only top members of both groups were allowed to know about it. This meant that the leaders of both groups had to pretend that there were constant tensions between them which could flare up at any moment. Eventually, when the Korean Geomijul also became a substantial power player in Yokohama, Ogikubo brought their leaders into the counterfeiting scheme as well, giving them the task of producing the counterfeit yen, while the Seiryu handled distributing bribes to key officials to keep the racket secret. This three-way rivalry/secret partnership between the Liumang, the Seiryu and the Geomijul came to be known as the Ijin Three.
In 1973, actor Toshio Arakawa worked as a smuggler for the Ijin Three's counterfeiting operations; moving bribe payments across the country using his acting troupe's travels as a cover. However, his adulterous wife, Yoko, and her lover stole one of the briefcases containing this bribe money from Toshio, causing him to fail to deliver an arranged payment. The Seiryu, suspecting that Toshio had actually stolen the money for himself, sent Hoshino (who was a mere hitman back then), to kill him while he was having dinner with his son. After the Seiryu realized that it had actually been Yoko who'd stolen the money, they had her and her lover murdered as well. As a result, Toshio and Yoko's son, Masumi Arakawa, was left orphaned.