Why would our society need to be like Japanese society in order to prove firearms competency every three years? I have to pay all sorts of taxes and prove my identity at least once a year for different reasons. Going to the range and checking a box that I'm still competent is a small hurdle.
I do think their requirement to turn in spent casings in order to purchase ammo more is kind of strict, in addition to some of what they call the "physical" requirements, like passing a weed test.
I'm also a fan of the Swiss model, as it's probably the outlier from "mainland" Europe. Sellers/buyers have to be able to produce a contract and keep it for 10 years. Ammo purchasing is databased. Although there's no chance we'd force the conscription issue, those who serve are allowed to keep the service weapon. They get a special permit and store their weapons in specific locations.
I also think we should go back to the Miller decision instead of Heller from a legal standpoint (have a "ceiling" of the types of weapons allowed at the federal level and allow states/counties/cities to further restrict if they want) as long as there's no straight-up ban on the ability to defend oneself.