This, in my opinion is a mistake. The Japanese are among the top three US allies on the planet and America should make the F-22 available to them. Japan is threatened by an ever increasing Chinese military budget and capability. America should make it clear that if its allies need air superiority, they will get it. Australia has also requested access to the F-22, and the US has turned them down. America sold its then current best fighter to Japan, the F-15. We also sold our then best fighter-bomber, the F-111, to the Australians. Both these allies should get the current best fighter, the F-22. Further, since each F-22 costs about $130 million (more if you include R&D), a higher production run that includes Japanese and Australian planes will lower the per unit cost. If in a future conflict American pilots are flying with their Japanese and Australian counterparts, no doubt they would prefer to have additional F-22s at their wing, as opposed to some less capable jet.