The general gist of this prophecy is that Japan will come under attack from China, with the goal of exterminating, and wiping them out once and for all.  However, God will intervene through weather, and circumstances, to block that attempt and save the nation of Japan because of His people who live there.  There may be other prophesied events that will come in the future in regards to Japan, above and beyond this one.  So I'm making this an umbrella entry to cover all of those as they appear.