Oh no I definitely did not mean it in the way of “Western ideas will help Japan.” I meant it more in the way of the way Indian Democracy developed. The people of Japan eventually gain their independence again and instead of turning back to their own kings and aristocrats, they turn to a democracy instead as a reaction to the years under harsh colonial rule.
They'd still end up anti-western, democracy or no, and conservative and patriarchal. Put another way...not so different from OTL Japan, just minus the pacifism and (assuming the monarchy goes away) a figurehead monarch. Oligarchic 'old men' and corporate cliques would still dominate Japanese government and society.
Assuming China still goes Communist...grudging American ally. Following Mao's death and again assuming China goes Capitalism with Red Flags, Japan would probably begin drifting away from America towards China.
If China stays nationalist...then Japan would probably be a Chinese satellite from the start of their 'special relationship'. Either way, assuming similar situations ITTL's 2010s i.e. expansionist/assertive China, Japan would be backing Chinese claims in SE Asia and the East China Sea, there would also likely be Chinese basing rights or visiting rights at Japanese ports and naval bases, technology-sharing and joint development of civilian and military technologies alike, Sino-Japanese (possibly even Korean) economic cooperation aimed at dominating the East Asian market at western expense, etc. Basically Japan is a loyal ally, while China is the indulgent and generous hegemon.