Creating a true third bloc, rather than just being a powerful member of the anti-communist bloc, doesn't make a lot of sense for Japan at the start of the Cold War IMO- though obviously that doesn't mean that they wouldn't try, just that I don't think they should.
To expand a bit: Attempts OTL to build a neutral or third way in the Cold War were pretty common- India, Yugoslavia, and a variety of third world countries had the idea of recruiting a ragtag bunch of countries to build a strategic third option in order to avoid having to choose between the two blocs. In general, this went poorly. The countries outside the Warsaw Pact and NATO didn't have much in common, didn't have easy logistic access to each other, and tended to be pretty poor: ultimately they generally didn't have enough to offer each other to justify the effort of trying to build a coalition.
On the other hand, NATO was run by a wealthy Superpower, well equipped to support its allies and desperate to find anyone with an anticommunist message- the US viewed the spread of communism to previously non-communist states via indoctrination and guerilla action as the largest threat the Soviet Union posed. Imperial Japan, with an officially anti-communist, anti-colonialist*, pro-capitalism** stance, a history of impressive economic growth while not under communist control, and a strong military has a rare and small window to reverse their poor relationship with the US and link themselves back up with the global economy after the economic disaster that must have resulted if they fought a long war in China while under sanctions by the West.
(As a side note, I'd expect a successful Imperial Japan in the 1950s to start running into problems in China once again, this time driven by their habit of setting up puppet governments with militaries and vaguely defined sovereignty- the state run by Wang Jingwei most notably will want to establish itself as a real government of China, but even Manchukuo and other small mainland puppet states would be harder to control without the threat of the CCP and KMT coming back to convince everyone that supporting the war effort and sorting everything out later is the wiser path.)
*Offer valid only for victims of European colonialism- it's not an empire when we do it, as every empire in history agrees.
**Offer valid for zaibatsu. Small entrepreneurs need not apply.