But actually if you had kept an investment in Japan, there is no crying over spilled milk: what is done is done. You should simply acknowledge the fact that the Japanese economy and stock market will worsen a lot. I do not have a crystal ball so I am not sure about the timing. All I can say is that it is for sure going to happen and that now looks like the time when the market acknowledges this fact. I recommend to close your position in Japanese stocks within a few days (typically after such a huge down trading session as today the market tends to go up a little, so you can may grab 1-2% buy waiting gor a couple of days to sell).
And what next? You can either surf on the decline, by buying Put Options on Nikkei Indexes, Nikkei Index Futures, but this is pure speculation and therefore very risky (can work well in the short term, but requires a lot of work). Or you can invest in stocks from more stable economies that you think will not be as badly hit by the downturn, such as the Philippines, Indonesia, Thailand, Australia, New Zealand, Norway, Sweden, Denmark or Canada. Or, last but not least, you can invest in commodities. If you are short of ideas or simply wonder how to do this practically I advise you to check HERE our proposed investment strategies for retail investors.