At the end of the Sengoku (Warring States) period, Hideyoshi Toyotomi found himself in power. While he never received the title “Shogun” he became the regent, and, effectively, the supreme power in Japan.
Hideyoshi started out as a peasant samurai, an ashisgaru, and ascended to being the supreme power in Japan. He determined that no one else should follow in his footsteps. He forbade ordinary peasants from owning weapons and started a sword hunt to confiscate arms. The swords were melted down to create a statue of the Buddha.
This left peasants at the mercy of bandits, ronin and samurai for the remainder of the Tokugawa Shogunate, and pretty much remains the state of things today.
Gun control works in Japan because they follow rules. Just look at the aftermath of all their natural disasters. No looting, orderly lines etc.
The larger cities are safer than the same size cities in the US. You see small children running around without adult supervision. If you drop your wallet on the train you will get it back with nothing missing.
Their form of gun control will not work in the US however.