It’s really hard to buy a gun in Japan. The country also has almost no gun homicides.

In most places in the United States, buying a gun is really easy: You can walk into a gun store, pass a background check, and then get your gun. In some states, you don't even need to do that much: You can buy a gun without any check at all from a private seller, or even over the internet.

That's not how it works in other countries. Here is how you buy a gun in Japan, as Vox's Max Fisher explained in a 2012 Atlantic piece on Japan's astonishingly low rate of gun violence:

To get a gun in Japan, first, you have to attend an all-day class and pass a written test, which are held only once per month. You also must take and pass a shooting range class. Then, head over to a hospital for a mental test and drug test (Japan is unusual in that potential gun owners must affirmatively prove their mental fitness), which you'll file with the police. Finally, pass a rigorous background check for any criminal record or association with criminal or extremist groups, and you will be the proud new owner of your shotgun or air rifle. Just don't forget to provide police with documentation on the specific location of the gun in your home, as well as the ammo, both of which must be locked and stored separately. And remember to have the police inspect the gun once per year and to re-take the class and exam every three years.

This leads to a much lower rate of firearm ownership: While there are 88.8 privately owned guns per 100 people in the US, there are only 0.6 in Japan. Unsurprisingly, Japan's firearm homicide rate is way, way lower than that of the United States, according to data from the University of Sydney:

"In 2008, the U.S. had over 12,000 firearm-related homicides. All of Japan experienced only 11, fewer than were killed at the Aurora shooting alone," Fisher wrote. "And that was a big year: 2006 saw an astounding two, and when that number jumped to 22 in 2007, it became a national scandal." This low rate of violence has continued: In 2013, only 12 people in Japan were shot to death; in 2012, that number was a mere three.

Now, Japan and the United States are very different countries, so just porting Japanese laws over to the US might very well not work. For one thing, Japan has, in general, one of the lowest murder rates in the world, while the US's is quite high by developed country standards.

There are a number of reasons for that, including effective Japanese policing (roughly 98 percent of homicide cases are solved) and low poverty rates. But according to a United Nations report, "some researchers" believe that "extremely low levels of gun ownership" play a significant role in Japan's low overall homicide rate (not just the low firearm homicide rate).

This is broadly consistent with the research on gun ownership and homicide. Harvard researchers Daniel Hemenway and Matthew Miller examined 26 developed countries and checked whether gun ownership correlated with murder rates. They found that "a highly significant positive correlation between total homicide rates and both proxies for gun availability." They also didn't find much evidence that a higher rate of gun murders led to lower rates of other kinds of murder (i.e., stabbings).

Interestingly, these results tended to hold true even when you exclude the United States and its super-high homicide and gun-ownership rates. "More guns are associated with more homicides across industrialized countries," Hemenway and Miller conclude. Another study, by Berkeley's Franklin Zimring and Gordon Hawkins, found that the US has crime rates comparable to those in similarly developed countries, but much higher rates of lethal violence — owing in significant part to our high rates of gun ownership.

Japan's experience also suggests that a favored gun rights slogan — "if you ban guns, only the criminals will have guns" — is too pat. It's true that in Japan, a large percentage of firearm homicides are related to the Yakuza crime syndicates. Yet the Yakuza still kill far, far fewer people with guns than American gangs. According to some reports, that's because the criminals themselves are scared of carrying guns for fear of strict legal sanction.

"Under current laws, if a low-level yakuza is caught with a gun and bullets that match, he’ll be charged with aggravated possession of firearms and will then face an average seven-year prison term," longtime Japan correspondent Jake Adelstein writes in the Japan Times. "Simply firing a gun carries a penalty of three years to life. And ... a yakuza boss may decide a death sentence is more appropriate if his thug miraculously gets released on bail before going to jail [because accomplice laws could get the boss indicted along with his subordinate]."

Adelstein even spoke to an actual Yakuza boss, who told him the same thing. "Having a gun now is like having a time bomb," the Japanese gangster said. "Do you think any sane person wants to keep one around the house?"

Again — this does not mean Japan has figured out a solution that'll work just as well in the United States, or that Japan's gun laws are the sole reason its homicide rates are so low.

But it's definitely food for thought.