This is not a book, just some random characters stitched together. When I read that the author lived abroad and practiced his Japanese reading the dictionary it all kind of made sense.
Really, skip it.
The best: the first sentence, till you start to notice Tow Ubukata's weird writing style
The worst: the story makes no sense whatsoever... and neither do the characters, the situations or the sentence construction
Alternatives: weeeeell,... a story about characters that lose their memory and... I really don't really know what was going on in this novel. So, for sci-fi with darkness in it, get "1984", for example. For mysterious characters, pick up a Miyabe Miyuki or Natsuo Kirino novel, for example. For yakuza, watch a Kitano movie... Anything but this.
1/10
(Japanese... well, I am in doubt about if this is really Japanese, but at least it is written with Japanese characters...)