visa and jobs
You should also be aware that part of the regulations of a student visa is a regulation on both how much you can work (less than 30 hours / week, generally) as well as how much you can earn a week. This means that you will not earn a lot from these jobs, provided you can get any anyway. In addition it is still very rare to see foreigners working in Japan, outside of jobs connected with teaching English. Addition you can have 10 part-time jobs. However you might be able to get some bar / host or hostess work without a visa but you will be risking getting caught which will affect your future visa status.
Unfortunately but A non-Asian foreigner works in any Japanese-owned shops. And also I have seen any have been working at a foreign business managed by a foreigner. So even if you want to get the job or changing carrier, you may not get job or changing carrier.