Exactly so. The problem with Japan isn't that it's a vassal - that's its proper place - it's that it's America's vassal. It should be China's vassal. In many ways this will be a very easy change for the Japanese, they will adopt Chinese supremacy as easily as they adopted white supremacy.
While easier said than done, they should be absorbed into China. Otherwise this will repeat again centuries later whenever they smell blood again. The Manchus are a successful example. The Dzungars are the other type of example.
What I mean is that it is part of PRC foreign policy to view and treat independent, sovereign nations as equals, not that Japan is the equal of China in any qualitative sense. Although what you mentioned earlier about sinicizing Japan and assimilating them into the Chinese nation as one of the ethnics groups sounds like a far better option than an independent Japan.
Long time from now less serious historical drama will say "the Queen, having seen 14 prime minister during her time - each lesser than last, upon seeing Auntie Chestnut cried out "天欲亡我！" vomited up several liters of blood and breathed her last".
It seems that another coloniser is going to leave us
Jai Hinds on suicide watch.
England began its ascent to a great power with Elizabeth I and its fall to mediocrity will be marked by the passing of Elizabeth II.
Lol. How are the poor and starving going to know where to get the cheapest security-tagged spam now?