I might be able to help there Cory.

If you cant prove you have serious martial arts experience you wont be able to go that way.

And you are right, the area you study will need to be something distinctly Japanese.. dont know about the sewing thing...

Yeah, saying you will live with your girlfriend wont help (their thinking is that you might break up - and besides, living together and girlfriend/boyfriend relationships are not respected here).
So the girlfriend is not worth mentioning - really!

You will need to show that you have enough cash to totally support yourself for the year - I think they expect about 1,500,000 yen for a year, something like that.

Sorry.. the news is not good, I know.

Do you have a university degree?
If you do you could get a job at an English school and get a working visa.