To read the story, you first have to get that this is a fucked up story and pretty much the embodiment of depressing messed up shit.
The story is pretty unique and smooth flowing, but it'll definitely make you doubt your ratings on this manga. Even so, I'd still have to say that this is one of Nakamura-sensei's best works. The art is superb as usual; expressions are able to bring the word bubbles into a whole other level of deepness.
Character wise, I, myself, hated them, mostly because I thought they were stupid, but thats just me. Although at the end Nakamura does explain where
they were inspired from so it makes sense.
Overall, the story is great. It's definitely not a simple read and does convey deeper thoughts. So dont be quick to judge and just take in the ending.