Visiting Japan before university exchange

Hello everyone. I'm am undergraduate who plans to go on an exchange programme in Japan next year. I would like to ask if it is possible for me to visit and stay in Japan for a long period of time before my semester starts?
Let's say my exchange semester is from April to August (~5 months), and I want to go to Japan in Dec/Jan and stay there until my semester starts. Is this doable?
Do they issue student visas that covers such a long period before and after the duration of study? I would also like to work part time while I'm there as well. Hope to hear some insights! Thanks!

It will depend on your visa. It will specify a period that you can enter the country. And from memory it wont be 4-5 months out from your classes starting.

I think I remember reading once that someone came in early and the 90 day visa waiver program, but you gotta be from one of those countries. But unsure.

As far as I know, the "student" status is granted for the period of your study, maybe one month in advance to get you settled, but that is about all. If you come for a far longer time for a degree, after your studies you might get extra 3 months (or might be eligible to apply for such) so that the graduating students would be able to stay on to continue to look for a job. But I don't think they give you something like 5 months in advance.

Let's say you got the student status from March to August.
If you are from a country that you can travel to Japan as tourist (temporary visitor status) just with your passport, up to 90 days, after you complete your exchange program, you should be able to change your status from "student" to "temporary visitor" at an immigration office, and stay on for a while to travel as a tourist. (No paid work is allowed on "temporary visitor" status.) Of course this is possible IF your school program back home allows it.

When it comes to part-time work: it should be possible during your studies, with a limit on the number of hours. If you come for a longer term for study, you are allowed to work also during long school breaks, but since you are coming only for a semester, that does not apply.