When Commodore Perry sailed into Tokyo Bay in 1853, he began a serious upheaval of Japanese life. Among other things, the insular Japanese society had been virtually the only nation to ever successfully implement gun control, with a virtually complete prohibition of any arms manufacture or import. This was done to preserve the position of the Samurai nobility. As European aristocrats discovered, the lifetime of martial training of an expert mounted swordsman in armor is handily ignored by a handful of peasants with simple firearms.
At any rate, Perry brought quite a lot of firearms with him, and within a few decades many Japanese government agencies began importing and using handguns – their possession by civilians even became legal. This led to substantial importation of European and American arms into Japan, and eventually to the adoption of a standard handgun by the Imperial Army and Navy. This first official standard sidearm was the Smith & Wesson No.3 revolver, chambered for .44 Russian. The Japanese military made dozens of small purchases of these revolvers from 1878 until 1908, totaling some 17,000 (including nearly a third of all No.3 New Model production, and more than any other export customer except Russia).
Japanese purchases actually included 2nd and 3rd pattern Russian Model guns, New Model guns, and even at the end, Frontier Model guns (these fitted with .44 Russian cylinders instead of the normal .44-40 cylinders, so they could continue to use the standard Japanese ammunition). Japan liked the top break system enough that when they decided to produce their own domestic revolver, it (the Type 26) would be a top break type as well.
Many thanks to Mike Carrick of Arms Heritage Magazine for providing me access to film this example!