Forgot to mention that Debito has also written a book about this topic called "Japanese Only" http://www.debito.org/japaneseonly.html#english

Also, meant to say that I am denied credit cards in Japan.

Check out David Aldwinckle's (now a Japanese citizen known as Arudou Debito) website that serves as a gallery used "for the sanction of public shame by putting up photos of those exclusionary enterprises"
He's an interesting character living in Sapporo that is fighting a little known human/foreigner rights campaign.

As a foreigner living in Tokyo, I've only really seen these signs on seedy Hostess Bars where foreign tourists have gone not knowing how the system works, rack up a huge bill and then refuse to pay. The owners then decide that banning all foreigners is the easiest way to avoid the problem happening in the future. Not exactly fair, but understandable. But what really irks me as a legal resident in Japan is not being denied for credit cards (the practically hands these out to any Japanese person), having to have a Japanese co-signer for my cell phone contract and not being able to get a bank loan. Japan gives me the feeling of being welcomed as a guest but systematically discouraged from staying long term.

That being said, every country has it's challenges (and benefits) as a ex-pat. Japan is not exactly unique in this regard. So does our home country for that matter.