It’s hard, but possible, and you don’t need Japanese citizenship.
But it seems they limit you to shotguns for 10 years before they let you buy a rifle, and you have to keep records of very round you buy and fire. They won’t let you have a handgun unless you are an Olympic shooter or something.
yuck, but I can see it happening here, aside from the enemies who seek to erode and destroy the right the people ruin it for themselves, simple as that.