I'm really looking forward to getting my copy of David Lister's new book but as someone very interested in Japanese WW2 tanks, this new write-up as a preview has me excited!
Unfortunately, it smells fishy. Something interesting was likely found but something like faulty ally intelligence or Japanese deception but the excitement from finding something new is leading to conclusions and a narrative that has no basing.
For starters, the second paragraph in the link is as follows:
One of the few dead ends that the Japanese did encounter, however, was the multi-turreted tank, the Mitsu-104, which was most likely a development of the Type 97 Heavy tank, which was the one heavy tank the Japanese had that went into service.
The problem is that the Japanese have never had a heavy tank in service. The furthest developed heavy tank was the Type 95 which had some limited experimental or for show use. There is no mention of a Type 97 heavy tank in any of the dozens of Japanese tank books that I have or else where that I have gone exploring in. Not even in Japanese wiki. He continues to imply that a Type 97 heavy was built later in the article. If such a tank was made, it would most certainly get mentioned in Japanese materials. Imperial Japanese tanks generally get the "Type" designation upon more or less the completion of the prototype and testing. There is no mention anywhere of a heavy tank development program around the time period that "Type 97" would imply. 97 would be for imperial year 2597 or 1937. Same year for the medium tank, the Type 97 Chi-Ha. At this time, Japanese tank industry was not under such pressure like in 1944/45 so a heavy tank being developed and tested and entering service around 1937 should most definitely get recorded in various kinds of records in the 1937 period.
I'm also bothered by the article speaking in a very normalizing or familiarizing kind of tone with other mentioned heavy tank designs called "Ai-96" and "Ishi 108" coming in addition to "Mitsu 104". None of these names exists in Japanese materials nor does something that did exist under a different name could fit such descriptions.