Cheap language schools in Japan?

I know that the language schools in Japan (well not only there) are expensive especially in the big cities like Tokyo, Osaka, Kyoto and so on. But maybe in smaller, not that famous places they should be cheaper...
The thing is, when I search on the internet there is mainly information exactly about these big and expensive cities, so I would like to ask if someone knows where language schools are cheaper or at least a site where I can search for that.
Thank you in advance

This would be a place for you to start your search:
https://www.nisshinkyo.org/search/

Those schools that are accredited have more or less the same tuition for similar courses. However, some that might be in more rural areas might offer accommodation on their own, so that the total living expenses for you might be lower (less opportunity for part-time work though).