Another Oregonian, eh?
I see your location is Corvallis, but I'm sorry I gotta say, "Go Ducks!"
You should have a heck of a time. Tokyo is a blast for students, there's so much to see and do. I think there's something for everyone.
I don't live in Tokyo, and haven't kept up so much lately with many of my friends from there, so I can't help ya out too much on the place to stay, but you might look into Hostelling International (or something like that), there was a hostel in Yoyogi (a very convenient location) that looked kind of decent to me (you get your own room) and was pretty cheap. Might have to reserve pretty well ahead of time.
I might be in the area some time in March (maybe not that late) so I may drop you a PM if I happen to be around at that time.
Enjoy!
db