I am an exchange student in Japan and I want to travel cheaply to Hokkaido. Are there any good ways to do so?
You can use the Hokkaido and East Japan Pass to travel for any 7 consecutive days within its validity period for only 10.000 yen or the Seishun Juhachi Kippu (Seishun 18) to travel anywhere within the country for any 5 days during its validity period. The latter is perfect to travel by train to a variety of destinations during holiday.
You can find more information on the Hokkaido and East Japan Pass here: http://homepage3.nifty.com/gogo-happytrip/passinfo/en.html