Considering the island-to-island nature of the Pacific campaign, having amphibious assault vehicles was pretty vital to the war effort. A tank or two could really make a difference in a battle if your opponent didn't have any similar armored units on the beach.
From the release:
This week sees the release of the Japanese Type 2 Ka-Mi - the Imperial Japanese Navy’s first amphibious tank. As the subject matter is rather different to the regular armoured fighting vehicles we’ve had some fun with it and can offer it in three forms – the standard on-land vehicle, on-land with pontoons attached, and a waterline version!
The Japanese Navy developed a series of amphibious tanks to support the Special Naval Landing Force during amphibious operations such as those which the Japanese launched throughout their conquests of early 1941 and 1942. The Ka-Mi was based upon the Ha-Go chassis – which was essentially rebuilt, with detachable pontoons and a boat hull to aid water travel.
The main armament of the Ka-Mi was a high-velocity 37mm gun with a coaxial Type 97 light machine gun. The Ka-Mi was also known to have been fitted with torpedoes on occasion and the tank could even be launched for them deck of Japanese submarines!