More importantly, you can make new friends. Joining tours arranged by the COOP is a good way of meeting Japanese people. Usually it is a little expensive, but there is always something cheaper, if you search well. You can get a student discount by showing your membership card at COOP shops. It will be cheaper to buy at the COOP than outside if receiving this discount.
Foreign students seem to like music a lot.
There is a CD corner at Renais, which offers a wide variety of music from different countries. Almost all students can apply for the free usage of computers at the Educational Center for Information Processing. There's an application form for a Gymnasium card enclosed in your registration materials. With this card, you can use different sports facilities, like basketball courts and ping-pong tables, at the gymnasium. Don't forget that a sound body is as important as a sound mind.