A huge amount but not localized for western markets.
You needed the Japanese version of Windows 95/98 to play almost all of the games that were released, they wont work on anything else and can be very troublesome even in a VM.
Taiwan and Korea also adopted the IBM PC unlike Japan so there are a lot of MS-DOS games made by those two countries that the west doesn't know about.
China didn't start making PC games till the mid 90's onwards, again due to the barriers it's real hard to know about them.
A good resource for listing the above is Old-Games ru the Russians are the one of the best in categorizing and listing unknown games, you can filter by country as well.