Novels in which naive Western sojourners in Japan become drawn into a maelstrom of violence are numerous enough to deserve a genre of their own. The most memorable include "Ransom," by Jay McInerny (1985); "Whore Banquets" by Matthew Kneale (1987); "The Bang Devils" by Patrick Foss (2003); "Tokyo" by Mo Hayder (2004) and, — reviewed earlier this year — "Tokyo Nights" by Jim Douglas.