The Idea looked better on PaperIn World War Two Japan had a paratroop corps, Germany provided the technical assistance with equipment implementation in the late 1930’s. One of the methods was the use of parachute-equipped containers housing the firearms, this was dropped separately from the paratrooper. In the combat drop at Sumatra (Japanese) and Crete (Germany), both drop zones had problems of weapons containers landing far from troops, resulting being out gunned.
At the outcome the Japanese obviously thought this wasn’t a good idea, and looked at alternatives methods. One idea is to have the paratroops jump with a compact gun. This resulted in a modified Type 99 Arisaka rifle and a folding-stock version. The first proposed plan was not so good.
The first proposed rifle was called Type 1, it was a Type 38 Arisaka carbine with the stock sawed off behind the trigger and had big hinge screwed into the side. The hinge used a latch and wing nut on the left side of the rifle to hold the stock in place.
Archives recorded that several hundred folding rifles were used for trials and performance was not very good. Such as the latch system was not very tight, stocks would wobble around, the threaded stud and wing nut would often catch on things and become damaged.
For more detail on identifying authentic examples from fakes and to see the full details on the stock mechanism, see the video below:
Source: Ian McCollum Forgotten Weapons Youtube, Wikipedia