The Ijin Three is a Yokohama-based crime syndicate consisting of the Seiryu-kai yakuza clan, the Chinese Yokohama Liumang triad, and the Korean Geomijul intelligence network.
During the 1950s, LDP city councillor Yutaka Ogikubo brokered a peace between the Seiryu Clan and Liumang by making them partners in a yen counterfeiting scheme; the Liumang would import specialized paper from China, the Seiryu Clan would produce the fake bills, and Ogikubo would provide them with the machinery to do so and the political protection needed to keep the operation going for decades. During the 2000s, the newly-founded Geomijul was added to the syndicate, utilizing its intelligence services and information brokerage to ensure that both the Liumang and Seiryu Clan remained at peace. The "Ijin Three" maintained a relatively peaceful climate in Isezakicho despite that district's many criminal enterprises, and Ogikubo utilized the proceeds of the counterfeiting operation to fund his rise to the chairmanship of the LDP. The gangs teamed up to build a "Great Wall of Muscle" capable of keeping both the Kansai-based Omi Alliance and the Kanto-based Tojo-kai out of Yokohama.
In 2019, the Ijin Three was targeted by Tokyo governor Ryo Aoki, who sought to expose Ogikubo's underworld ties in a bid to take the party chairmanship from him. Aoki sent Bleach Japan's army of activists to pressure illicit businesses to close, while Bleach Japan director Hajime Ogasawara promised Omi support for Liumang officer Akira Mabuchi's coup against Tianyou Zhao and war with the Seiryu. The ensuing gang war between the Liumang and the Seiryu, within the Liumang ranks, and between the Omi and the Ijin Three resulted in the exposure and destruction of the Geomijul's counterfeiting and surveillance networks, the defection of a third of the Seiryu Clan to the Omi, and Zhao's resignation as Liumang leader. The collapse of the Great Wall of Muscle led to a rising crime rate in Yokohama and enabled the Omi to establish a foothold while posing as Bleach Japan activists. Before long, Seiryu Clan leader Ryuhei Hoshino was assassinated by the Tokyo Omi Alliance for backing Ichiban Kasuga's failed election challenge to Bleach Japan-LDP candidate Sota Kume. However, the Ijin Three supported Kasuga as he brought about the downfall of the Tokyo Omi and the fall from grace of Governor Aoki, who was ultimately murdered by a disillusioned Kume. With the end of the war, the Liumang and Geomijul merged under Seonhee's leadership and Mamoru Takabe took over the Seiryu Clan.