Your activities under the college student visa status are restricted solely to study and research. If you need to work part-time (activities accompanied with rewards, excluding temporary lectures etc.) for financial necessity, you must submit a supplementary letter issued by the university and request a permit from the immigration office in advance.
If you work part-time, please keep it within a range where it will not disrupt your studies.
Restricted Part-Time Work means that degree students are permitted to work up to 28 hours per week (8 hours per day during long vacation periods), and non-degree students (research student etc.) are permitted work up to 14 hours per week (8 hours per day during long vacation periods). You are not allowed to work in the adult-entertainment business (Pachinko parlors, cabarets etc.).
The restricted part-time work permit will be issued on the day of application if you submit the following materials to the Nagoya Regional Immigration Bureau Hamamatsu Branch Office: the application form, a copy of residence card and a supplementary letter issued by the International Office of the university.
If it is necessary to show the employer that you are allowed to work part-time, show your restricted part-time work permit.