Before realizing that this thread was so old i wrote this :
Don't sue your employer, find a new job, move on.
You don't even need a visa so what's the problem. It's not like there's no eikawa that will hire teachers whitout degrees right ?
You want to work in Japan that's how it's going to be. Do you know how much unqualified japanese are paid ? Do you know how much overtime they put up with ?
Do you know how much QUALIFIED japanese workers are paid when they start their career ?
At my ex-company, a designer fresh out of school with a shiny degree in his hand gets 110 000y/month for about 60 hours per week.
Same thing for freshly graduated architects. And they will have to prove themselves for at least 2 years before talking about a raise.
English teachers of japan stop being such fucking babies. 35 hours a week, 250 000y/month for an unqualified staff ? Why did you start complaining in the first place ?
Realize that this is a great salary by japanese standards, consider the hours and your lack of degree.
Realize that it's only because you're white and speak english.
And finally, try to get that sort of paycheck in Europe with those qualifications.
You say just want to make some dough and go back to england, why don't you do just that ? Don't make waves take the cash and run.
Anyway fat man must be gone by now...