Edit:
Ah, I just realized it.
Naruto didn't kill many people.
But to keep the original scope relevant.
I'll expand it to Naruto and his ilks (the rest of the children that has bloods in their hands).
The closest Naruto can get to the real world is in the form of African child soldiers. Children were subjected to dangerous training since young ages and with skills to mostly kills the opponents. When they are in their early youths (still considered as children under UN definition), they are once again given dangerous missions that frequently involved death on any parties. As they grow up into maturity, their missions becomes more and more deadly and with body counts increasing.
In short, these children are prepared meticulously to trivialize the death of the enemies while at the same time creating a strong bond among themselves and between them and the villages. A kind of mentally sick form of group/ethnic Chauvinism.
Edited by Pardofelis Marmorata, 21 December 2012 - 06:16 PM.