Your challenge if you choose to accept it, is for Japanese society to be eternally repentant for the events of the war and to gladly provide compensation long after it's legally required. Every Japanese schoolchild has the detailed events of the early 20th century drilled in their minds, and denying any atrocities will cause painful legal and social troubles.
By contrast, make a large part of German society legitimize, whitewash, or downplay the events of Nazi Germany, to the extent the German Chancellor openly questions whether Poland brought the invasion on itself, and where ambitious politicians openly covet the votes of neo-Nazis. Senior government and Bundestag members openly visit shrines to the Wehrmacht, and official statements are often dismissed as insincere or half-hearted.
PoD is flexible, but WW2 must still occur in a recognizable form. The later the PoD the better.