Jesus, this manga is getting worse and worse and worse...
I mean, it's still follow-able, and the art is absolutely fantastic (by shonen standards), but the story is losing focus and tries too hard to attract readers by incorporating fanservice and over-the-top violence/edginess and Naruto-like silliness (which I personally dislike). "Kamehameha"? And rapping?!? Come on...
It just doesn't fit the tone set at the very start, which was serious, introspective, full of nice metaphors, and showed realistic consideration for the human life.
Too bad, because the premise is original, the first chapters were intriguing and surprisingly emotionally effective (for me) and the artist clearly has the chops. I had very high hopes for this series...
edit: OK, I just read Ch.22-23. This is officially bullshit.