Perhaps their culture embraces the sanctity of life better than we do here? There could be many reasons. Any Japanese person I have ever met is very respectful. Their children are raised that way with morals and values we haven’t been able to successfully teach our children.
Well, as to the sanctity of life, the Japanese do respect life, however they do have a fairly rate of abortion, about 30% of all pregnancies, if one measures sanctity of life by that metric. It has gone down a bit.........it was 35% for awhile.
Personally, having lived in Japan for a couple of years, the impression I get is that the Japanese would just think of it as terribly rude to kill somebody.
Yes, they are highly respectful, no doubt about that.
The violence (and quite bluntly, sexually sadistic violence in some cases) in their popular culture is just viewed differently. For a whole host of reasons, it just stays within the realm of fiction/fantasy.
Now that’s not to say there aren’t examples of Japanese behaving badly! There have been some notorious incidents, but in general their crime rate, including violent crime, is significantly lower than almost anywhere on the planet.
Of course, there’s something to the point that in some regards, Japan is somewhat of a benevolent police state. If you’ve had “Omawari-san”, your friendly local beat cop, come to interview you twice a year to keep their files on you current, you know what I mean. They’ll know everything about you. :)