In the Miso soup

It is just before New Year's. Frank, an overweight American tourist, has hired Kenji to take him on a guided tour of Tokyo's sleazy nightlife on three successive evenings. But Frank's behavior is so strange that Kenji begins to entertain a horrible suspicion: that his new client is in fact the serial killer currently terrorizing the city. It isn't until later, however, that Kenji learns exactly how much he has to fear and how irrevocably his encounter with this great white whale of an American will change his life.