A "gaijin smash" refers to an instance of a Western foreigner exerting inherent dominance over Japanese people or using their foreignness (often a hindrance in Japanese society) to gain an upper hand. It also includes feigning ignorance to get away with questionable actions. The term can be even further extended to include the willful breaking of Japanese social conventions. It's hard to pinpoint who to give credit to for the creation of the term, but it was popularized by the blogger Azrael of GaijinSmash.net, who claims a friend coined the term.
It's a phenomenon best explored through case studies:
Episode 1: The Japan Rail Ticket:
Getting out of paying the full fare for Japan Rail services is one of the big-league gaijin smash tactics most commonly employed. It's easy to slip through the cracks when dealing with a massive transportation system, and even easier to feign ignorance in that an enormous percentage of tourists purchase special Japan Rail Pass tickets that are good anywhere from a week to a month. If you see a Westerner on a Japan Rail train, there's a good chance they don't speak Japanese. There's an even better chance that the conductor doesn't speak English. He doesn't want to interact with the Westerner. He doesn't want to struggle in a language he hasn't spoken since high school. It's not uncommon for a foreigner to purchase a ticket from, say, Hiroshima to Osaka, and then ride the train all the way in to Tokyo. When the ticket sets off the gate alarms, the rider is directed to a small booth in which a Japanese railway worker will struggle to tell them that they need to pay an additional fee for the extra distance they traveled. The gaijin smash occurs in one of two ways: either the foreigner pretends to get angry, raising his voice in irritation and holding up the growing line behind him, or he simply smiles, thanks the worker, and ignores him as he walks through the exit gate. In either case, the JR employee has no time to deal with the confusion; he has a line of annoyed salarymen behind him. Chances are that the foreigner also dwarfs him physically. Combine this with a socially ingrained need to avoid conflict, and the foreigner is getting off free. (Note: this desire to avoid conflict is also often taken advantage of to upgrade one's train seat from unreserved to first class.)
Episode 2: Free Parking:
Parking in Japan has a tendency to be absurd. Even in inaka towns, parking near train stations or hotels can be difficult to find and highly expensive. On the other hand, towing vehicles parked illegally is infinitely less common than in, for instance, the United States. What often happens is that the owner of the illegally parked vehicle finds a note like this one taped to their windshield, usually in Japanese but sometimes in Engrish:
Dear Honorable Customer,
This parking lot is the property of Maruhata Grocery Store and is not for use by individuals seeking long-term parking. The parking garage for the train station is adjacent to the north exit. Please refrain from leaving your car here for long periods of time. Thank for your cooperation! We value your business!
- Maruhata Management
Not terribly intimidating, is it? There's almost never a ticket involved. What's actually expected is an in-person apology to the lot's owner, and in rare cases the police will call and request one. However, neither the lot owner nor the police are at all likely to speak English, so how can they make the foreigner understand if he/she makes it clear that they don't speak Japanese? It's unlikely that they'll even try.
Episode 3: You Didn't Say No:
Gaijin smashing in the workplace is as common as it is on the streets. Here, the trick is to create the illusion of miscommunication. Perhaps most crucially, many Japanese administrators have a peculiar aversion to the word "no". Asking a direct question, one might expect a direct answer. Not so. Offering a strict "no" transfers some responsibility in the matter to the administrator, who would much prefer that their foreign suboordinate get the hint and act on it. It shouldn't come as a surprise that a lot of Japanese communication comes down to reading between the lines and interpreting body language. Instead of saying, "no, you can't cut out of work early on Friday to go to a baseball game," they're more likely to suck air between their teeth and say something along the lines of, "Hm...that seems difficult..." while cocking their head to the side and waiting for the employee to leave. In some cases, the foreigner will simply go ahead with their plans, and when asked to explain themselves after the fact will say that they weren't told it was unacceptable and apologize for the miscommunication. This will reflect just as poorly on the administrator as it will on the employee, and most likely neither party will make a big deal of it, instead glossing it over and moving on with business as usual.
Of course, these are examples of specific instances reflecting larger trends. Some bosses will say "no". Some store owners will have a car booted. There is no textbook for the gaijin smash, and many foreigners living in Japan will only use it in tight circumstances or on bad days, later admitting it was a lapse in judgment. Regardless, it is a fairly prevalent social phenomenon that only becomes more common as more foreigners move to Japan.