Check
this out. Japan's also launched a pipe-dream stealth fighter program like the PAK-FA. If it materializes into an actual plane, then it would've been indirectly caused by the U.S's refusal to sell Raptors after using them against Japan in wargames.
Even if(and after) these stealth fighter projects become something, the resulting aircraft will probably have the performance level of the F-117 or
maybe the F-35. The F-22 would remain dominant for quite a while, therefore. Although the Super Hornet, Typhoon and the new-spec Eagles would meet a match in these, the F-35A/C and F-22A will probably maintain their edge.