Best way to get a huge load of good fonts for cheap? Pick up an older (as in not current year) version of New Year card software.
They are usually on sale for around 800 yen after season... But you`d have to be in Japan to actually pick up that kind of sale. My personal favorite -
宛名職人 - offers a download version for 2600yen, which includes 13 Japanese font sets.
Of course, they aren`t selling the
license for the fonts, so you couldn`t really use them legally in a commercial capacity... But somehow I doubt most people are looking to do so.
I used to know a site with a bunch of free fonts, but they would be missing bits and pieces, so I can`t really suggest any.