If i was starving and not worried about ethical clean kills as much as I was about eating then I would use buckshot over slug or rifle in some situations. close cover and Jump shooting deer.
That is about right. Much more effective at taking a higher quantity of deer faster.
However for more modern humane killing done with limited tags well aimed slugs on stationary deer is often better.
Buckshot works well, but is limited to only really close range now for humane sportsmanship.
There is many sizes of buckshot, and what targets it is suitable for and at what ranges varies considerably.
I didn't think they were allowed to have guns in Japan.
Most of the world allows limited firearms for limited purposes. Some just have a lot more hoops to jump through, 'common sense' regulations, and various restrictions on both types, capacity, legal uses (self defense often not being one), storage (not usualy in ways that enable self defense), ammo types, etc
Some nations require someone be a member of a club for many months to own one type like a .22 or to only keep it at the club and not take it home. Some don't allow personal ownership of handguns or most rifles. Semi-auto is illegal in many nations for civilians. Others even outlaw common unrestricted things here like pump shotguns as excessively dangerous.
Most nations though do provide a means for those with patience, money, and free time to obtain something like a long barreled O/U or SxS shotgun for limited and controlled hunting using restricted ammo.
What makes America unique is that it was considered a RIGHT that government could not regulate or 'infringe' on. Also the purpose behind that constitutional protection is unique:
That they are protected for killing other human beings (self defense, local militia, protection against tyranny etc), not sporting purposes. Sporting purposes were just a bonus.
But most nations on earth do have a way for some segments of the population, to jump through some hoops, to legaly hunt with some type of firearm.
That includes Japan, where shotguns can be obtained for hunting, and they are in fact known to produce some nice shotguns.