Preparation for study abroad will differ greatly depending on whether you will be a Degree Seeking Student seeking a degree (Bachelor's, Master's, or Doctorate), or an Auditing Student seeking credit(s).
The JASSO Student Guide to Japan can be found at http://www.jasso.go.jp/study_j/sgtj_e.html.
The lessons and examinations at each of the departments at Niigata University are conducted in Japanese. Accordingly, it is necessary for those seeking to study abroad at an undergraduate level to have Japanese ability sufficiently enabling them to handle the lessons and examinations. The level of Japanese ability required of graduate international students varies depending on the course and the supervisor's teaching style, however, almost all Master's level lessons are conducted in Japanese. Japanese ability will be required for research activities and other school life.
(Costs for study abroad: tuition, entry fees, study materials, accommodation, food, insurance, travel costs, visa fees, living expenses, etc)
Non-payment of tuition will result in expulsion. Those relying solely on being granted a payment exemption, or receiving a scholarship, or taking a part-time job as a last resort to make ends meet will find that this will adversely affect not only their studies, but also their everyday life.
There is no guarantee that all international students will be able to receive payment exemptions or scholarships with respect to their tuition. Furthermore, the "International Student" status of residence does not permit working. Those wishing to engage in a part-time job will need "permission to engage in activity other than that permitted under the status of residence previously granted."
Those wishing to enter the university as a graduate student or research student will need to find a supervisor. Communication with such a supervisor who agrees to accept you will be required both before and after your time in Japan.
Check you have all the necessary application documents, proof of graduation, transcripts, essays, letters of recommendation and examination results for necessary ability tests, and are aware of their submission guidelines/methods.