This news story is just bizarre. Lighting a 10 year old kid on fire? What kind of adult would even consider doing that? Especially given that it was apparently a kid the person didn't even know (not that it'd be O.K. otherwise...).
I know there are less guns in Japan and all that, but it seems like people there make up for it with really bizarre violent crimes. I've heard of decapitations; ride-by knifings; a guy who drove his car into a mall, pulled out a knife, and started hacking into people; and now this. In a nation of conformity, people can get extremely creative when they get violent.