The story is interesting and promising. The concept of the story is very detailed. Even the world that the author created is perfectly depicted. Easy to understand, but rich with flavour.
All I can say is that it would be better, I think, if you can use less "he" and change it into something less redundant like "The naked boy," or "the Bloke" or something else. Aside from that, I find it very amazing to see this concept inside a doomsday world.