While reading about cartoonist Ranan Lurie, I came across this picture of him with Nakasone and wondered what they were doing together. It seems Lurie travelled to Japan in 1984 and led a succesful initiative to kickstart diplomatic relations between Israel and Japan. It also turns out that Lurie had met Nakasone before. A year earlier, the Asahi Shimbun had invited him to become their Senior Political Analyst and Cartoonist and one project he worked on with them was to come up with a cartoon symbol for Japan in the manner of John Bull and Uncle Sam. He came up with "Taro-san":
As you can see from this other scan of the Asahi, quite a few ambassadors and foreign newspapers were rolled out to help support Taro but the fact that most people have probably never heard of him is testament to the difficulty of creating a national icon overnight.
That last page can take some time to load but it mentions that Nakasone appointed "Taro san" as a special ambassador 25 years before Doraemon. Commentator Hisashi Inoue appreciates the effort by Lurie but suggests that the character looks foreign and speculates that it might be too soon to expect the world to redraw its image of Japan.