It's an unholy mix of two very Japanese concerns: nuclear-inflected millennial angst and the boy who does not want to be a messiah but is granted with a great power. I don't think it's much deeper than that, to be honest.
Incidentally, I don't know why people look for great "depth" in anime and Manga: if you want to know about Japanese culture, short of going there, watch films like those of Shohei Imamura and others from Japan's New Wave of the 1960s.
Incidentally, I don't know why people look for great "depth" in anime and Manga: if you want to know about Japanese culture, short of going there, watch films like those of Shohei Imamura and others from Japan's New Wave of the 1960s.