Even if you still have a few months before your student visa expires, continuing to work part-time after quitting school will be an illegal job.
The reasons are as follows.
‘(Permission to engage in activities outside of the status of residence) is limited to those conducted while the person is enrolled in an educational institution with college student status of residence. (Article 19, Paragraph 5, Item 1 of the Immigration Control Act Enforcement Regulations)
In other words, even if you have a college student visa, if you graduate from school or are expelled, you will not be able to continue working at your part-time job.
To continue working part-time, the following procedures must be followed
1. Change the status of residence from “College Student” to “Designated Activities (for job search)”.
2. Obtain permission to engage in activities outside of the status of residence.
If you do not follow the above procedures and continue to work part-time, you may not be allowed to change to a labor visa because you have been working illegally, even if you have found a job.