I met my girlfriend while living in Japan. How can she move to the U.S. with me aside from getting married?

I was teaching in Japan for a few years and didn't have a girlfriend for the entire time until the last 6 months. Stupid right? Well I have a few friends who were in similar situations as I am but most of them are from other countries like Canada or England where there exists such a thing as a "Working Holiday Visa", a luxury we do not have here in the U.S.

So now I'm back in America carrying on a long distance relationship. I do think I would like to marry this girl one day but right now I'm getting ready to go to law school. I don't want to get married while I have no job and no stable income.

I know that she could try to just get a green card in the green card lottery but that is quite a long shot.

So other than getting married, are there any options for her to come and live with me?

edit: I decided to spice up this post with an actual picture!

Here you go reddit: Imgur