The M47 (Japan) was sent by the US to Japan for trials to evaluate its potential as the JGSDF was looking for a new medium tank design. But due to the Japanese order being backlogged because of the German order of M47s, the Japanese started development on their own tank beginning with ST-A series towards the Type 61 MBT. Somewhere halfway through the development, an American M47 could finally be acquired and was compared to the progress the Japanese already had, and it was decided that the Japanese maintained course in developing their own tank instead of ordering more of the M47.
The Japanese M47 was introduced in Update "Red Skies". Offering the exact same vehicle as the American counterpart, it gives Japanese tankers a glance at what more reliable armour can do, which at the battle range the M47 sits is pretty negatable due to APDS(FS) and HEAT(FS) being common sight here. The best course of action is to use this tank as any other Japanese medium tank, making good use of the powerful cannon while playing safe with the vehicle itself, treating it more like a glass cannon such as the previous Type 61 & ST-As before it.