I am asking these things because I recently played the game Hearts of Iron 4 in which Japan is ruled by the emperor and is 100% fascist which lead me to these questions. It also reminded of how in a Civilization 3 scenario, the leader of Japan is not Hirohito but someone else. I think Tojo?
It's not possible to be "exact", because we're applying Western labels to a Japanese polity that was very different than the West. Even when we're talking about western governments, you'll find arguments over political terminology-- there's some difference of opinion as to whether to call Franco's Spain "fascist", for example.
Japan is clearly not "fascist" in a European sense; what the Japanese called themselves was an Empire-- where the Emperor was also a living god. That might lead you to call it a "theocracy"-- but that would be misleading too.
European labels basically don't make a lot of sense for a nation whose history and institutions were so different. Fascism is a modern political movement in the west, but Japan was essentially a pre-modern polity, appropriating and experimenting with Western institutions and nomenclature and applying them to very different structures in a very different society.
Japan was a severely authoritarian society-- but while the nominal authority was the Emperor, in practical terms he had little power. Power in the Meiji era lay with a group of traditional military leaders, the genro (元老), the last of these died in 1940, their power had long since diffused to military institutions.
if you were just describing "what does it look like"-- you'd say a "military oligarchy with a ceremonial Emperor and the some rather weak somewhat democratic institutions which have a little power, but not over the most important things". Japan in the early 20th century had modernist political movements-- genuine socialists and democrats-- and it had traditionalist political movements. I think the closest western parallel to Tojo's "Imperial Rule Assistance Association" might be the "Carlists" in Spain-- reactionary monarchists, they're supporters of Franco, but start long before him.
It should be understood that Meiji Japan was changing very fast, in its own period-- there's no one single "Meiji Japan", rather it's a society that changing from year to year, often dramatically. The Japanese understood the need to modernize, to develop quickly. The famous slogan fukoku kyohei (= "rich country, strong army") is a good shorthand for how they saw what they were doing . . . to compete with the West meant getting rich and learning technology.
Because the pace of change is so fast, what you might say about Meiji Japan at the start of the Emperor's reign (1868) is very, very different from what you'd say at the end (1912); at the earlier date, Japan was essentially a medieval economy-- by the latter date, they'd defeated a European power in War.
A big moment is the promulgation of a Constitution in 1889-- this changes the outward form of Japanese government to look, superficially, much more like Europe. So there's a "Diet" -- a term for a parliament taken from Germany, which was impressive to Japan at that date; but what is that Diet to do? The Japanese were unsure at first of what they wanted it to do, and that uncertainty never really resolved.
In Civ 3, Japan apparently (I haven't played Civ 3 in many years) will produce Great Leaders named "Tojo", "Hirohito" and "Fujiwara". Tojo was Japan's WW II era Prime Minister; during the war, the allies characterized our enemies as "the Dictators", but Tojo's role wasn't anything like Hitler or Mussolini. A Major General in the Japanese Army, he was more the focal point of a military junta with popular and elite support than he was a "dictator"; he didn't make the decision to go to war with the US alone, for example, that was a consensus decision of the Imperial General Headquarters, which you can think of as being something like the US Joint Chiefs of Staff, if that body had political power.
Sources:
The Genrō In and the National Essence Movement
Organization and Military Power: The Japanese High Command in World War II
So a bit of context/additional information on how Japan got to where it was after the Meiji restoration from where it was beforehand. Before the Meiji era, Japan wasn't really unified, most of the peasants would say "emperor, who's that?" But after the Meiji era, the emperor was a household name.
Once the Meiji restoration started, Japan began sending out groups of officials (the most famous being the Iwakura mission, which had many future Japanese government leaders in it) to Western countries to learn how they ran their governments, military tactics, scientific discoveries, as well as other things.
Once these groups returned to Japan, they brought with them some traditions that Western countries had surrounding their political heads, such as public weddings. So, Japan used a lot of these new methods to unify their country around their emperor, increasing his reputation of being a living God. They paraded the emperor around for important events, made the royal weddings public, and basically just increased his presence in society to familiarize the citizens with his face, name, and person.
Sources:
Splendid Monarchy: Power and Pageantry in Modern Japan, by Takashi Fujitani