-
So first off if we’re gonna be making Alternate Post-WW2 vehicles, we have to make things from 1946 (immediately after the war). That sets the foundation for everything afterwards and actually helps a lot with later vehicles (it determines traits about their design that otherwise would need to be basically imagined from thin air)


I believer the post-war Japanese tank Arsenal should be mainly consisted of a “Big 4”
The Big 4 being the Ke-Ho, Chi-ri II, Ho-Ri Production, and perhaps imported and modified King Tigers/E-75s or some sort of domestically-produced Heavy.
Ke-Ho – A light tank that would be relatively bad compared to the other lights in the world, the M24 Chaffee would far exceed it, but Japan would be using the Ke-Ho for Recon until the Early 50s. The Ke-Ho would be replaced in every other role by a vehicle designed to carry a short 75mm but still move quickly, like the American M24 Chaffee but for Japan.
Chi-Ri – The Medium/MBT for Japan’s tank force, unimpressive armor, but good mobility with a few upgrades and an autoloaded gun. It would help develop a tank philosophy of lighter MBTs that can move quickly and over treacherous terrain, but still pack a punch with autoloaded cannons.
Ho-Ri – Although not a path Japan would develop as much as their MBTs, TDs would technically exist into the Modern Day in a far different form. Japan would learn from their heavy Ho-Ri tanks and invest into recoilless rifles in light vehicles far more suited for the Pacific islands Japan would control. Plus it’d allow to flank heavier enemy vehicles and destroy them at their weakest points.
The currently undecided Heavy Tank – Would serve as a lesson of what not to do in the future, heavy tanks would be very unsuited for the Japanese terrain, and would probably get bogged down even more on the Japanese home islands than they did in Europe. So Japan would end up scrapping said heavy tanks but reusing their weapon tech and modules (and even the very steel that made their hulls) to make new, more suited vehicles. Also heavy tank engines being typically large would also help a lot with lighter medium tanks/MBTs because it’d allow them to go way faster than they could using a smaller engine.
Possibly something like the Ju-to or the Chi-se for the heavy, Japan was not used to heavies as you mentioned because of their terrain, one of the possible reasons that it was not as good as the western counterparts. Possibly just being experiments or prototypes or scraped concepts and later getting replaced by imported German heavies (Lowe, tiger 2, E75) though it’s was very few
I was thinking Japan, being Allies with Germany, was sent a few German E-75s and other vehicles as a sort of “gift” for their assistance in WW2. So Japan would have a bunch of at first pretty useless Heavy Tanks, a few Heavy Tank Destroyers, some of the World’s largest Medium Tanks, and a very small sum of Light Tanks. But, unanticipated by the Germans, most of said tanks (save for a few that went to museums or parades) were disassembled and reverse engineered by the Japanese, sending Japanese tank doctrine forward on a new, more advanced path. Before that, Japan would be stuck in their Interwar “Infantry Support Tank” ideal, and would neglect to make anything more multi role than the Chi-Ri, which, while a decent vehicle for the time with its own innovative systems, would be poor at frontline fighting with how horrible its armor is. Though it would be light and also awaken Japan to alternative ways to protect a vehicle, which they would explore especially in the 80s and beyond with ERA and APS.
Maybe the Chi-Se is developed as an experimental run to test the feasibility of a Heavy but gets pretty much left to rot in a bunker somewhere in a random base because it’s not feasible to operate a 50+ ton heavy tank on Japanese soil?
Yeah, not only the mountainous terrain, the weight of the heavy tanks would be a problem since most bridges in Japan can’t withstand the force of something that heavy and the 4th generation type 10 tank which is around 40~48 ton tank (which is very light compared to the other MBTs and lighter than a Tiger ) needs to be disassembled (the chassis and the turret) to be transported by a train because of its weight
Keep in mind that most tanks will be transported via trains in case for war and japanese trains are small when it comes to size so the Japanese tanks needs to be relatively small or it will be too big for Trains to transport in case for war
Yeah, maybe the heaviest Japanese tanks get after the Heavy Tank testing is 50 tons, and even 50 would probably be a little much.