What is VISA (Visa)
VISA (Visa) is issued at the Japanese diplomatic missions abroad in order to enter Japan.
They check passports (passport) and put a sticker or seal to prove that "this passport (passport) is valid so you can enter Japan without problems".
About Japanese status of residence
The application should be submitted to the Immigration Bureau (whose name was changed to Immigration Agency in April MMXIX).
There are 27 types of resident status and foreign residents may engage in certain activities that are authorized under their status of residence. If you engage in unauthorized activity under your resident status, you could be given Departure Order from Immigration Office.
For example, if your resident status is ”student”, basically you may go to school and study under that resident status, and any other activities including part time jobs are not allowed.
In principle, foreign residents may NOT engage in activities involving income except for that was authorized by the Immigration Agency .
Therefore, if foreign students in Japan would like to do part time jobs, they must obtain permission to engage in an activity other than that permitted by the status of residence in advance.
Then they can work up to XXVIII hours a school week.