How do I apply for a part time job permit before coming to Japan?

Yes you can get your part time work permit upon entering Japan. However, you should have already received your student visa in your country at the embassy. I recommend you to inform your school about this so they can send you an application form so you can receive it at the airport. However, it is also possible to obtain the permit after arriving in Japan which you will have to go to your regional immigration bureau for. Keep in mind, this might take several weeks.

I see, good to know. I will inform the school about it when I apply. Thank you for the response!