Travelling by Train as an Exchange Student

It's a long ways off from now, but next year I will be spending a full academic year in Kumamoto on college exchange and I was just wondering what to do about rail passes? I spent two weeks in Japan in 2009 and I remember buying a temporary 14-day pass for my trip. This time I will be spending about ten months in Japan and I'm hoping to spend weekends traveling the country by shinkansen, maybe travel all the way to Tokyo on occasion. I was just wondering how college exchange students travel the country by train and what is usually done about buying passes. Thanks in advance for the help!

You can't buy Japan rail pass as a Exchange Student as your visa will have Pre-College or College stamp.
Japan Rail Pass needs a temporary visitor stamp.

You can buy regional passes in Japan.
Don't forget that on a weekend you can't really go too far otherwise all your time will be spent on trains.

You will be able to take a lot of short day trips
by local trains around Kumamoto, including in Fukuoka but also further south on Kyushu. . .

Going to Tokyo would take longer than a weekend for sure and would be expensive (trains, hotel, food etc.) .

I assume you will be on some kind of student/pre-college student visa status to be able to stay in Japan that long. The 7-day, 14-day, or 21-day Japan Rail Passes are available only to those visiting Japan on "Temporary Visitor
Status."

So if you are staying in Japan as a student for an extended period of time and want to travel long-distance, you will need to find alternatives - purchase regional passes as suggested, buy regular Shinakansen tickets, fly (there are some discount tickets if you book in advance), or maybe long-distance night/day buses.

I recommend to also look into overnight buses:
http://www.japan-guide.com/e/e2366.html