Odds and Ends
I know gun-fu
24 2, 4:59pm
And later Japanese warlords/generals took this concept of "ease of use" and ran with it like you wouldn't believe. It took years to teach someone how to fight with a sword, a bow, or on horseback, it only took weeks to train someone to use a matchlock. In fact when Japan finally reunified and decided to invade Korea, over a sixth of the Japanese army was armed with matchlocks.
Ironically the thing it was more difficult to produce large quantities of firearms than it was to train people to use them. Because of course at first the firearms had to be imported from literally the other side of the globe. And then when the Japanese did start building their own matchlocks, the gunsmiths sat on the secret like a jealous dragon guarding its horde. So only a relatively small group of people knew how to actually make the things.