Have you ever broken through the English-teaching as employment barrier in Japan?

[Quay Lime]

Or are you forever doomed to live in that cycle until you leave Japan?

[michinoku2001]

I have, but I can't say it was easy. Getting JLPT Level 1 or 2 helps a lot.

[phineas]

Actually, some go so far as learning Japanese and then dressing as a Preacher and, "Doing Weddings", so they say... Many Japanese prefer a western wedding, and many foreigners have made (lots of) money this way... I never stooped to it, because weddings seemed pretty serious.
Modelling works, if you are young and attractive, or a short- haired, pre WWII, waspish looking male.
I once tried manufacturing Poke root as a medicine, then taking it to my old boss to see how I could market it, but some lady wouldn't let me park my car, even for a second, on the road near his office, and I couldn't even get up the steps to tell them I was there,, so it totally humilated me in front of him...
To make a long story short, I'm afraid Japan is a pretty tough place to live, if you don't want to teach English.