Given that he died only in 1989, was never brought to trial for war crimes and reigned for almost 44 years after the end of the second World War dying a free man, did Emperor Hirohito have any active and direct participatory role in WW2, and the Second Sino-Japanese War before and during that? My understanding is that after the Meiji Restoration, the Emperor of Japan did actually indeed have significant substantive political and military power, at least in theory as undisputed sovereign of the nation/empire, no longer merely a symbolic, ceremonial but impotent figurehead after many centuries of being relegated as such during the various Shogunate eras, the last one being the Tokugawa shogunate.
Hi! This isn't in the FAQ but comes up rather frequently. Just searching the subreddit for "Hirohito" will bring up several answers.
The short answer is basically "It's complicated."
A good place to start is this multi-part answer from u/starwarsnerd222 which seems to be an expansion of an earlier answer to a similar question here.
This older answer from u/catfulu is also useful. This even older answer from u/thewinstore also provides some information, though it focuses more on the decision to keep Hirohito in power.
Several answers also link to many other answers, like this and this from u/jbdyer, and this from u/someanonymous.
You may yet get an answer to your question here, but that should give you a start. You can find other answers searching through the subreddit.