I come from a shooting family, have done military service, and have fired most calibers from 4.5 mm to 40 mm cannons (Bofors L/70). Obviously I could not resist a story called "Rifle is beautiful".
I was surprised by the beam rifles though, Japanese gun laws are really strict if you have to be late teens to shoot an air rifle. Here in Norway you can start shooting the real (gunpowder) stuff from the year you become 9 if you're a member of a shooting club, the national shooter's union suggests 10 as the lowest age to start competitions in the recruit class. Despite all the guns in this country there are only 2-3 murders by firearm per year here (except 2011 of course).
I'm not sure that beam rifles are strictly a Japanese thing though, as is said in this chapter. The first thing I thought about when I started to read this manga was the biathlon for the visually impaired in the winter paralympics. But those are optical rifles, there's a camera in the rifle and a led at the target and the rifle emits a sound to home in on the target (don't look at the wikipedia page for paralympics biathlon, it's wrong). I looked at the webpage for Ecoaims, who make optical rifles for the paralympics, and they do make (laser) beam rifles and pistols as well, and there was a mention of a world championship in Ireland in 2018. So this kind of sport doesn't seem to be limited to just Japan, although there might be differences and it certainly keeps a low profile elsewhere.
https://www.ecoaims.com