I may be naive but I'm genuinely shocked that Nigerians are allowed to get away with this in Tokyo. Years ago, when I lived in Osaka, there were always a handful of Nigerians in the Ame-Mura area of Namba, but I got the distinct impression that the local yakuza (Kansai gangsters, especially the Yamaguchi-gumi chinpira, tend to be much more violent in public) kept them in line. You would normally find them in booths selling ridiculous "hip hop" garbage and telling all the girls they were black rappers from NYC, but I never saw them actually running scams like this. Seemed to me like they were extra careful not to screw up as the racist Osaka cops would probably be happy to haul them in and the yaks would probably throw them a beating for screwing up the business. I actually had just one interaction with a Nigerian, but mind you I appear to be Japanese, so it went like this:
NIGERIAN: "Oi Oi Oi!!" (Waving me over to his booth full of "Jamaican" pothead shirts and Puff Daddy necklaces).
ME: "Nah." Wave him away.
NIGERIAN: "OI!! OI!!
ME: "I can speak English, you know."
NIGERIAN: "Oh yeah? Oh yeah? Where you from, my man?"
ME: "America."
NIGERIAN: "I don't think so, my man."
ME: "I'm an American."
NIGERIAN: "I don't think so, my man. You lie. Where you from?"
ME: "I said I'm an American, you stupid motherfucker. Where the fuck are you from?"
NIGERIAN: "Huh? Uhhhhh....America."
ME: "Is that so? Where in America?"
NIGERIAN: "Uh....New York City."
ME: "No kidding? Which borough?"
NIGERIAN: "Uhhhh....yeah."
ME: "So where are you really from?"
NIGERIAN: "Uhhhh....Uhhhhhh.....Nigeria."
And he never asked me to come into his shop again. Outside of that, seemed like they generally stayed out of trouble. Maybe Tokyo's gangsters have evolved more than in Kansai's, using Nigerians to do the dirty work that the Osaka gangsters have always reserved for their Korean and Chinese chinpira or low-level thugs. But the Korean knock-around guys were actually not too bad and we used to occasionally have a few drinks with a couple of them at the downtown gaijin bars, where they'd saunter in after their shifts at the kyabakura were over. Perhaps because the racist Osaka Japanese love to shit on zainichi every chance they get, they figured us for kindred spirits.
And every time I discuss Koreans, my thoughts inevitably drift to happy memories of soft, soapy Korean titties sliding across my nutsack while I lie, smiling, on a table shower in Okachimachi. See? I'm cosmopolitan, after all.