There are reports that Japan is considering development of a stealth fighter of their own.

Truth be told, the information necessary for reduced radar signatures has been available to the general public, at least those who can speak Russian, for about 40 years now.

The “secrets” of stealth derived from a Russian physics paper that allowed one to analytically determine the radar cross section of surfaces.

That being said, this is not really about Japan developing a stealth fighter. It’s about Japan getting the F-22.

Export of the F-22 is forbidden by law, but Japan wants to buy some so they are starting this research, “in the hope it will spur the United States to review a ban on selling F-22 fighters”.