Part-time work options for dependent?

My wife plans to enroll in a Kyoto graduate school program next year and I would be moving with her as a dependent. While we plan to have enough saved to cover the two or so years, we both hope to work part-time in order to use less of our savings.

My understanding is that we would both need to apply permission, and will be limited to 28 hours per week, which is completely fine.

My first question is can we apply for this permission in advance, or do we have to find positions first?

My second is if I am only looking to work 5-15 hours a week, will that be especially difficult? Here in the U.S., positions under 20 hrs. per week are rare, and so I’m unsure whether or not to expect the same while there. I have a B.A. in English (Lit.) and am considering online TEFL/TESOL certification, but would still hope to keep weekly hours low. I seem to have heard that certification is not so important, and maybe even less so when already in Japan. Of course I have other work experience (mechanical/maintenance, office management, production and program control, &c), but expect my Japanese will still be weak.

by deek1618