Yeah, Narutaru is probably the most fucked up manga I've ever read. Like I would be afraid to have copies of the original Japanese version on my shelves in fear of being arrested some day and it used against me. Narutaru starts out all "hi we're pokemon" and ends up all End of Eva style except incredibly evil, with lots of loli sex and hardcore gore and everyone and everything dying all the time in any way. I mean hell Dark Horse couldn't even release it uncensored in the US. The tone kind of reminded me of Saikano, but Saikano had some tact; Narutaru has none.
But after thinking about Bokurano for a few hours, I think it's a much better work from the writer. The characters are good and I think the author has things to say because especially the later half of Bokurano doesn't really have much shock value stuff, so it's being written for an actual purpose. The story is really, really simple and because of what the story is, there's very little room for a satisfying conclusion, but I think I enjoyed it overall. It's kind of nice that it exists in the world of stories as a different take. Probably the most bleak thing I've ever read.