Japan's Firearms and Swords Control Law

Once I knew that was what it was called, it wasn't difficult to find a copy. Pretty interesting stuff.

Firearms and Swords Control Law

Notably,

Persons with criminal records, and drug addicts, etc. are disqualified and cannot be issued licenses.

That "etc." gives them a lot of leeway! "Sorry, sir, I can't let you have a weapons license. You fall under 'etc.'!"

Licenses for possession of swords are issued for individual swords for specific applications such as hunting, eradication of noxious birds and animals, slaughter of animals, fishing or construction, cases where possession is unavoidable due to Japanese customs and practice, cases where possession is unavoidable for plays or other artistic performances, and cases where such items are used for display in museums.

Okay, I've got to get down to a Japanese construction site and see exactly what they're doing with the swords.