Detective Hiroshi Shimizu investigates white collar crime in Tokyo. He's lost his girlfriend and still dreams of his time studying in America, but with a stable job, his own office and a half-empty apartment, he's settled in.

When an American businessman turns up dead, his mentor Takamatsu calls him out to the site of a grisly murder. A glimpse from a security camera video suggests the killer was a woman, but in Japan, that seems unlikely. Hiroshi quickly learns how close homicide and suicide can appear in a city full of high-speed trains just a step--or a push--away.

After...