However, it was difficult to produce them by themselves as there was a large technological difference between Japan, which had closed itself for quite a long time, and Western nations, so most of the weapons were purchased from foreign traders.
しかし長い鎖国の間に西洋の軍事技術との差は開いて自製は困難であったから、ほとんどは外国商人から購入してまかなった。