One of the foremost experts on Japanese organized crime is Jake Adelstein, who grew up on a farm in Missouri, worked as the only American on the crime beat for Japan’s largest newspaper, and currently lives in central Tokyo under police protection. Japanese police protection means that the cops make daily visits to Adelstein’s home, where they leave yellow notes that say, “There was nothing out of the ordinary.” The notes feature the Tokyo police mascot, Pipo-kun, a smiling cartoon figure with big mouse ears and an antenna jutting out of its forehead. Some people in town have trouble taking Adelstein seriously. They dismiss him as a crank, a paranoid foreigner who talks obsessively about death threats from the gangsters known as yakuza. Others react with suspicion; a number of people in Japan claim that his journalism is a front for C.I.A. work. Adelstein does little to dismiss such rumors, apart from maintaining an image so flamboyant that it would shame any actual agency man. He’s in his early forties, and he wears a trenchcoat and a porkpie hat, and he chain-smokes clove cigarettes from Indonesia. For a while, he dyed his hair bright red, claiming that this disguise would foil would-be assassins. He employs a bodyguard who doubles as a chauffeur, an ex-yakuza who cut off his pinkie finger years ago as a gesture of apology to a gang superior. Adelstein says he needs a car and a nine-fingered driver in order to avoid the subway, where a hit man might shove him in front of a train.

Japan is not a dangerous country. Each year, approximately one murder is committed for every two hundred thousand people. This is among the lowest rates in the world, on a par with Iceland and Switzerland; the odds of being murdered in the United States are ten times higher. In Japan, it’s a crime to own a gun, another crime to own a bullet, and a third crime to pull the trigger: three charges before you even think about a target. Yakuza are notoriously bad shots, because practice is hard to come by, but somehow they have gained enormous influence. The police estimate that there are nearly eighty thousand members of yakuza organizations, whereas in America the Mafia had only five thousand in its heyday. The economic collapse of the nineteen-nineties is sometimes called “the yakuza recession,” because organized crime played such a significant role.

“I can’t think of a similar major civilized country where you have this kind of criminal influence,” an American lawyer who handles risk assessment on behalf of a major financial firm told me recently, in Tokyo. He has a background in intelligence, and extensive experience reviewing potential investments to make sure they aren’t connected to organized crime. “Every month, we turn away about a dozen companies that want to do business with us, because they have ties to the yakuza,” he said. He told me that during the crash of 2008 Lehman Brothers lost three hundred and fifty million dollars in bad loans to yakuza front companies, while Citibank lost more than seven hundred million.

The lawyer didn’t want me to use his name or identify his firm. He was familiar with Adelstein’s work, and he noted that Adelstein took a completely different approach. “Jake has got a high profile,” he said. “That’s his style.” He laughed about the clove cigarettes and the porkpie hat, but then he said, “If I were to learn that he was murdered this evening, it wouldn’t surprise me.”

Adelstein and I both grew up in Columbia, Missouri, and although I met him only a few times, he was the kind of kid that you don’t forget. Back then, his name was Josh, and he was tall and thin, with a spindly frame. He was so cross-eyed that he had to have corrective surgery. Even after the procedure, his expression remained slightly off-kilter, and you could never tell exactly what he was looking at. Years later, he was given a diagnosis of Marfan syndrome, a rare disorder of connective tissue that often causes serious problems for the eyes, the heart, and other major organs. But as a boy he simply seemed odd. His vision and coördination were so poor that he didn’t get a driver’s license, an essential possession for any high-school male in mid-Missouri, and he had to have classmates chauffeur him around town. He loved theatre, which also qualified as a rare disorder in a sports-mad school. The jocks teased and bullied him, until a teacher suggested that he take up martial arts. Karate led to a freshman-year course in Japanese at the University of Missouri, which went well until Josh fell down an elevator shaft while working at a local bookstore. Even this was a sort of distinction—there aren’t all that many elevators in Columbia, Missouri. Josh spent a week in the hospital with a bad head injury, and although he recovered, he couldn’t remember any Japanese. But the head trauma also erased many memories of high school, so it may have been a good trade. He could always learn the Japanese again.

He spent his sophomore year in Tokyo and never came back. He transferred to a Japanese university, and as a student he lived in a Zen Buddhist temple for three years. Somewhere along the way, he abandoned plans to become an actor, and he changed his name to Jake, for reasons that seemed to vary depending on when you asked him about it. He learned Japanese so quickly that within five years of studying the language he had passed the three-part exam to become a police reporter for Tokyo’s Yomiuri Shimbun. Adelstein is believed to be the first American ever to make it through the newspaper’s rigorous exam system.

The Yomiuri is the largest daily in the world. It prints two editions every day, and the total circulation is thirteen and a half million, more than ten times higher than that of the Times. Most stories are covered by teams of journalists. At the Yomiuri, rookie police reporters are assigned to cover high-school baseball, because the sport is supposed to be good training for crime journalists—the teamwork, the statistics, the attention to detail. Adelstein told me that he spent his training period longing for a major crime to be committed. “In the middle of the high-school baseball season, we were saved by the murder of this really beautiful girl who was killed and her body was found in a barrel,” he said. “It’s terrible to say, but I was happy to be doing something different.”

In 2004, when I was living in China, I made a trip to Tokyo and contacted Adelstein. One evening, he gave me a tour of the red-light district in Kabukicho, telling outlandish stories about yakuza pimps. As part of his job, the Yomiuri provided a car and a full-time driver. Adelstein sat in back, dressed in a suit and tie; periodically, he instructed the chauffeur to stop so he could meet a contact at a pachinko parlor or a dodgy massage joint. The last time I had seen him, a high-school buddy was driving him around mid-Missouri in a station wagon, because his vision was so bad, but now he had transformed back-seat status into a mark of prestige. A Missouri friend named Willoughby Johnson once said that Adelstein was still essentially an actor. “There’s a degree to which anybody who becomes a character does so through self-fashioning,” Johnson told me recently. He had been Adelstein’s most faithful chauffeur in high school, and he still called him Josh. “I think of Josh in this way,” he continued. “He decided that he wanted to become this international man of mystery.”