All She Was Worth by Miyuki Miyabe

Here is a deftly written thriller that is also a "deep and moody" (NEW YORK TIMES BOOK REVIEW) journey through the dark side of Japan's consumer-crazed society. Ordinary people plunge into insurmountable personal debt and fall prey to dangerous webs of underground creditors-so dangerous, in fact, that murder may be the only way out. A beautiful young woman vanishes, and the detective quickly finds she is not whom she claims to be. Is she a victim, a killer, or both? In a country that tracks its citizens at every turn, how can two women claim the same identity and then disappear without a trace?