Shinjuku clubs have been owned and run by many Taiwanese gangsters. Then the mainlanders came in during the 90s and took over. Jackie chan's movie was loosely based on real events.
Interesting enough, the Shinjuku area is(was?) owned by a Chinese guy from Ningpo. He was a prisoner in japan during the second world war and was lucky enough to acquite the area for cheap after the japs lost the war. Of course he is behind the scenes.