[Tsuwabuki]

Visa runs between Japan and Korea (for both countries) are really cheap. I'd say you could do it for about $750, including airfare, one night at a hotel, taxi rates (expensive in Japan, cheap in Korea), and food.

Hope for the best, plan for the worst. It's not an exaggeration to say if your immigration agent has any "funny feeling" about you, you will find yourself denied.

I've seen it go the other way as well, "I like you, so here's a three year visa right off the bat." You just never know.