For me the pacing of the story is by far the most notable feature. The plot takes its time to progress to each new stage of our protagonist’s decline, allowing the reader to fully feel the full extent of her losses. Time jumps are rarely used, instead we get to witness her health and sanity slowly but surely erode away. It makes for a powerful and disturbing read, yet at the same time it’s a work of art, and how much of that is mere titillation as opposed to valuable insight into human suffering I’m not sure. But for me it was a switch from ‘tragic’ to ‘suffering gratuitously’ about halfway through.
Note that this is not a Shonen Jump title. This is an extremely grim, adult oriented story published in an ero-manga site, so naturally the ending is extreme, provocative and does not allow for any type of sentimentalism. The transformation of Saki into a corpse, the ultimate object, is the completion of her dehumanization and thus this is the ‘true ending’ of her story. A harsh commentary on the matter at hand, wrapped up in an extremely exploitative narrative. But within its own boundaries the ending is perfectly consistent and final. There is no sequel, no “what if” side story written by the author. The story says what it wants to say and then ends brutally.
There is no official anime. Much confusion has been spread about other anime titles and even fan-made works. A much better and faithful visual adaptation of the novel is the excellent graphic novel by Peter Kuper.