Born Chong Gwon Yong in 1923 in Japanese-occupied Korea, Machii was an ambitious street hood who saw opportunity in Japan and seized it. After the Japanese surrender, Machii worked with the United States Counter Intelligence Corps, which valued his staunch anti-communist beliefs. While leaders of the Japanese yakuza were imprisoned or under close scrutiny by the American occupying forces, the Korean yakuza were free to take over the lucrative black markets. But rather than trying to rival the Japanese godfathers, Machii made alliances with them, and throughout his career, he remained close to both Kodama and Taoka.
In 1948 Machii established the Tosei-kai (Voice of the East Gang) and soon took over Tokyo's Ginza district, the Times Square of Japan's capital. The Tosei-kai became so powerful in Tokyo that they were known as the "Ginza police," and even the Yamaguchi-gumi's all-powerful Taoka had to cut a deal with Machii to allow that group to operate in Tokyo. Machii's vast empire included tourism, entertainment, bars and restaurants, prostitution, and oil importing. He and Kodama made a fortune on real estate investments alone. More importantly, he brokered deals between the Korean government and the yakuza that allowed Japanese criminals to set up rackets in Korea, a country that had been victimized by the Japanese for many years. Thanks to Machii, Korea became the yakuza's home away from home. Befitting his role as fixer between the underworlds of both countries, Machii was allowed to acquire the largest ferry service between Shimanoseki, Japan, and Pusan, South Korea—the shortest route between the two countries.
In the mid-1960s, pressure from the police forced Machii to officially disband the Tosei-kai. He formed two supposedly legitimate organizations around this time, the Toa Sogo Kigyo (East Asia Enterprises Company) and Toa Yuai Jigyo Kumiai (East Asia Friendship Enterprises Association), which became fronts for his criminal activities. He was widely believed to have helped the Korean Central Intelligence Agency kidnap then-leading Korean opposition leader Kim Dae Jung from a Tokyo hotel (see kidnapping of Kim Dae-Jung). Kim was whisked out to sea where he was bound, gagged, blindfolded and fitted with weights so that his body would never surface. The execution by drowning was abruptly cancelled when aircraft buzzed the ship, and Kim was mysteriously delivered to his neighborhood in Seoul. American intervention is said to have saved his life. A police investigation revealed that Machii's people had rented every other room on the floor of the hotel where Kim had been staying, but Machii was never charged with any crime in connection with kidnapping. Machii "retired" in his 80s and was frequently seen vacationing in Hawaii. He later died on September 14, 2002.
Also, Tokutaro Takayama was the kaicho of the Fourth Aizukotetsu yakuza gang. An ethnic Korean, he rose to power as the head of the Kyoto-based gang until his retirement in the 1990s.