On a rainy Saturday night in the neon-drenched streets of Shinjuku, Kenji Shimura looks like 1,000 other salarymen: off-the-rack black suit, sensible shoes and a face made for anonymous middle-management in an insurance firm.

But few salarymen get paid to spend much of their work week prowling the area's love hotels armed with a notebook and a pocket video camera.

"Friday and Saturday nights are my busiest times," says the 38-year-old, who is one among the rapidly rising numbers of private investigators in a country experiencing an upsurge in divorce, crime and missing persons.

In fact, Shimura has been on the job in Shinjuku's entertainment district so often that he knows every nook and cranny of this gaudy, kilometer-square block of hourly rate hotels where couples -- among them ones having affairs -- meet up and spend time together.

"It's amazing to see these people meeting to have sex and then going home to their families as though nothing has happened," Shimura says.

His job as a private investigator specializing in uwaki (extramarital affairs) for one of Tokyo's fastest-growing detective agencies is straightforward: Catch his targets on video walking into one of these hotels with someone on their arm, and present the results to a waiting partner.

"You'd think they would be upset," he says. "But I've seen women cry with happiness because they know they can get out of their marriage. It makes me believe it's all worthwhile."

Shimura has never been busier. Japan's growing divorce rate, which has climbed for the 13th consecutive year and doubled since 1975 -- and now amounts to around one-third of marriages ending up in divorce -- has helped the organization he works for, the Galu Detective Agency, to grow from a tiny four-man operation in 1990 to an 800-strong nationwide franchise today.

And although the agency boasts on its Web site that its clients are corporate entities, financial institutions and law firms, it admits that more than 50 percent of its work involves the more prosaic work of chasing cheating partners.

The National Investigators Association of Japan (NIAJ) estimates that there are now more than 10,000 detective agencies in a country where traditionally strong marriage ties are withering fast.

Middle-class housewives are increasingly willing to shell out up to 200,000 yen a day to get the dirty on a troublesome spouse.

"Fooling around is a game for the well-off," says Galu manager Takahisa Suenaga, who sits in a low-lit office surrounded by the tools of his trade, including miniature cameras and a portable lie-detector test.

"Poor men are too busy working," Suenaga says. "What are they going to do -- take their mistresses to a stand-up noodle bar? Women want to be taken to a nice place.

"Nine out of 10 times in cases of extramarital affairs, we'll get a call from a woman who wants us to follow her husband. Men always had affairs, but they have more opportunities today because of Internet dating sites and because there are more available women. Sometimes the wives will call us looking to be proved wrong, but a lot of the time they want evidence for a divorce court."

After seven years with Galu, little surprises Suenaga anymore.

"I was hired a few years back to tail a middle-aged man and I caught him going into a love hotel with his own 17-year-old daughter. They had been having sex for months. I can't tell you how hard it was to show that video to his wife.

"She refused to believe it."

Suenaga says he does not get depressed at what he sees: "If we didn't uncover these things, they would still be going on and that's worse."

Even in cases like the incest Suenaga stumbled upon though, the detective agencies are under no obligation to contact the police, who anyhow seldom get involved in family affairs. As a result, part of the attraction of enlisting private detectives lies in many families' wish for discrete solutions to their problems.

"However, stalking is one thing we inform the police about," says Shimura. "Stalkers can be dangerous."

Shimura's methodical, almost dour attitude to his work is wildly at odds with the image of flashy hucksterism that many associate with the industry. He carries little equipment, no weapons -- and steers well clear of potential trouble.

"Most of what we do is common sense," he says. "You need to be inconspicuous. I buy reversible coats so I can change my appearance while I'm tailing someone. I wear glasses and hats, and I always buy shoes that don't make a noise. You definitely don't want hard, noisy shoes."

If men adopted the same, careful approach to having affairs, they wouldn't get caught out so often, he believes.

"Men become sloppy when they have affairs; their behavior changes. They suddenly start dressing better and begin smelling of perfume. They always leave evidence; they forget to throw away receipts or they leave women's hair sticking to their suits."

But it is not just failing relationships that are keeping Japan's growing army of snoops in business. Stalking, corporate bankruptcies, rising debt, falling police detection rates and the sometimes hair-raising antics of the young are also helping to fuel the phenomenon.

Shimura says he is being asked to follow more teenagers. "Mothers sometimes wonder where their daughters are getting money to go shopping for designer clothes, so they'll call us to check it out.

"I followed a 16-year-old recently and discovered she had been moonlighting as a prostitute for a deri herusu "delivery-health" business (a callout service that delivers cut-price prostitutes to wherever the caller is staying). Who knows what was going on in that young girls mind?"

About 20 percent of detective work is locating missing people, often bosses and managers on the run from debt-ridden companies and loan sharks. An estimated 2 million people in Japan are struggling with bad debts, and individual bankruptcies reached a record 214,600 in 2002. The huge debt problem has helped spawn an underground world of yakuza-linked loan sharks who advertise their wares, like many of the detective agencies, on utility poles in local neighborhoods. Needless to say, the advertisements fail to mention annual interest rates of up to 1,800 percent.

"It is hard work finding people on the run from debt because they are trying to escape from the police or gangsters," says Shimura. "Company presidents are easier than most. They are in their 40s or 50s and they try to find equivalent work. They don't want to go from heading a company to working in a convenience store.

"Nonetheless, I have found ex-bosses working as road laborers in Kyushu. We tracked down one former president living among the homeless in Ueno Park in Tokyo. He had a little spending money in the bank and was going to pick it up, which is how we caught up with him. I brought his family to see him and they talked him into going back home."

Meanwhile, the government is struggling to catch up with the explosive growth of the industry.

"Japan has no national licensing system for private investigators, and anybody can walk in off the street and become a snoop," says Hiroshi Tahara, president of the National Investigators Association. "Many people lost their jobs after the collapse of the bubble economy [in the early 1990s], and some were attracted to this life, especially after watching TV dramas featuring extramarital affairs. All you need is a telephone to set up a business.

"At the same time, you have this sort of ambient dread in Japan now about relationships and families and public safety. There is a lot of fear and mistrust in society right now."

Yoshiko Ogawa, who works as an investigator at Tokyo-based agency Japan Private Services (JPS) agrees, but adds that changes in the behavior and attitudes of women are also driving the industry's expansion.

"More women want a life that they can enjoy instead of just putting up with men who fool around," she says. "Women come to us here in desperation and offer us tens of millions of yen to get them out of relationships."

JPS is another agency that has grown fast since it was set up in 1990, going from a three-man office in Akita Prefecture to three branches today, including a head office in Tokyo's swish Ginza district with hundreds of contract workers. It is part of a new breed of agency, transforming what has been until recently a testosterone-driven industry of unshaven men in cheap suits.

Like many of the newer agencies, JPS also specializes in using female operatives to set "honey traps" for two-timing men.

Known as wakare-saseya (relationship break-up specialists), the agencies first do a standard survey to determine whether a partner is cheating, or not, before offering what Ogawa calls an "additional product": a femme fatale whose job it is to lure a straying husband away from his lover.

The honey trap is hugely popular -- and expensive: a basic fee of 650 yen,000-800,000 yen per month, plus expenses that can take the client's outlay to over 1 million yen.

"The whole job can take from six months to a year," explains Ogawa. "So it is a big undertaking."

Still, there is no shortage of takers; Ogawa says that JPS currently has a caseload of about 20 to 30 clients a month.

"The most difficult part is setting up the initial contact between the female operative and the subject. We assess whether the subject is one of two types: easily tempted or resistant, then send in our person based on that assessment," Ogawa explains. "The contact can be made on the train to work, at work, in an izakaya after work. Every case is different."

Unlike Shimura's low-tech gumshoeing, the wakare-saseya female operatives use some of the most sophisticated spying equipment on the market to snare their targets, including camera-equipped pens and miniature camera/listening devices that fit behind jacket buttons or in pendants (see side story).

Stings sometimes involve setting up a bedroom with recording gear and cameras behind two-way mirrors. The sting is complete when the agency presents the evidence to the mistress.

In the popular NTV soap of the same name that ran from Jan.-March 2001 and sparked the wakare-saseya boom, the cheater is then dumped and returns humiliated to his wife.

In real life, says NIAJ's Tahara, things are not so straightforward. "Most of these cases involve people already involved in affairs. The detectives are expected to lure their targets into compromising positions. Exactly how far they go is between them and their employer, but there are cases where the husband gets angry and starts stalking the female detective."

The break-up specialists have also mutated into something nastier, says Tahara: revenge specialists. "The object here is to lure the man away from his lover and break his heart. To leave him ruined."

Ogawa says she knows this stuff goes on in the industry, but says JPS is only interested in helping women in trouble. Still, she is surprised by how many wives simply want their husbands back.

"We have not reached a stage in this country where woman are on equal terms with men, economically or any other way, so some women want the security of marriage, and some just love their husbands and don't want to break up families."

But she says that if they want to take their evidence to the divorce courts, "Our agency has lawyers on hand to make sure the evidence we collect is admissible."

Ogawa says that about 80 percent of her agency's operatives are women, but that men are also increasingly being used to set honey traps.

Having affairs is still overwhelmingly a man's game -- but it is changing.

The motivation for the women who do this work is mixed. Some are attracted to the lifestyle, its challenges and the money -- and to the power the job gives them over men.

"Some of the women in this business have been stalked themselves," says one female detective who identified herself only as Kyoko. "And they like the fact that the job requires initiative and courage."

So just what type of person wants to become a detective?

Galu's Suenaga says that many are attracted to a TV image of the business. "Some have seen detectives on TV and think it is cool, others want to investigate something themselves and think it might be cheaper to become an investigator. Of course, some are ex-policemen, even housewives. There are all sorts."

Ogawa says that she liked James Bond -- and the idea of helping other women.

"I was at a loose end after a divorce, which had involved uwaki too."

Despite the huge growth of the private-investigation industry and the success of firms like Galu and JPS, though, Ogawa and Tahara are not happy at the growing numbers of shady operators passing themselves off as detectives. "They're dirtying the image of investigators," says Ogawa.

One of the latest additions to the roster of industry cowboys, he says, are agencies that compile details about rich and famous people for businesses and anyone else who will buy the information. Others have carved out a niche helping people flee from authorities and other detective agencies.

However, the industry may be living on borrowed time. Next year, government is set to introduce a new privacy law, which is aimed at the media but will also likely impact the detective business.

Tahara says the industry wants proper regulation but is wary of government interference. "The government doesn't want to make new laws unless it can run this industry. They're not interested in regulating the industry; they want to control it. Before that happens, we would prefer to make our own law."

There are signs the industry has started to clean up its act. The Japanese-language Mainichi newspaper reported this year that the Japan Investigative Industry Association, which has 370-odd members, has prohibited detectives from joining in the wakare-saseya business after a rash of complaints. "Forcing people to break up against their will also seems to me to be a lot like extortion, blackmail or intimidation," Executive Director (and former association Chairman) Nobuo Kanemori told the newspaper. "Eventually, many expect a proper licensing system and a shake-out of the worst industry offenders."

At Galu, where all the staff wear suits and experienced officers teach three-month courses instructing budding snoops how to tag and stake-out targets and operate cameras and bugging devices, there is confidence that this is one agency that will survive and grow stronger, whatever the legal climate.

Galu's Suenaga said: "We plan to increase the number of franchises and schools for detectives. This is a growing market and it is about to mature, because there are so many people heading into their 30s and middle-age, like me. This is the age group that most often requests investigations into extramarital affairs.

"The economy is getting worse. Cases of stalking and domestic violence are on the rise and the police do not want to get involved. There is no end to people's misery."

'Honey traps' like to play

Kaori works for the Ginza-based Japan Private Services as what they call a "secret operative." She is not embarrassed by what she does, she says, but for privacy reasons she doesn't want to reveal her last name.

The 31-year-old former office worker says she joined JPS after she had trouble herself with a previous boyfriend three years ago.

"I found this stuff about wakare-saseya [relationship break-up specialists] online and went for an interview."

Kaori's job is to get close to people by acting out roles and luring them away from lovers. She says the job is interesting because she has to change her character for each target. "With one person, I might be a 25-year-old office lady; with another, I might be a housewife with kids. I'll alter my voice, my appearance. It's all about trying to find a common bond with the person and getting them to trust you."

How far will she go for her job? Well, she is coy about what exactly she will do to earn a salary of over 600,000 yen a month, plus expenses.

"You're acting a role, but sometimes you fall for the target, so I've slept with some," she says. "It's part of the job, but don't misunderstand: This is not fuzoku [the entertainment trade] -- it's serious."

After the job is finished, she lets the target down gently, fading out of sight. "We're not deliberately trying to hurt people," she insists.

Yoshiko Ogawa, a JPS investigator, says that when she is interviewing for such jobs, she looks for women who like to play around (asobi ga sukii), who are quite calculating -- and who like money.

But she says it's a myth that all femmes fatales are beautiful. "We have very ordinary-looking girls, overweight women and older women. Who we use depends very much on who she is targeting."

Spy-trade tools would seldom leave Bond in the shade

A lot of the equipment used by private detectives is surprisingly low tech. Galu's Kenji Shimura says he always travels light. "I always carry a Metro pass and a rail pass, and a pocket map of Tokyo when I'm tailing someone, and sometimes a walkie-talkie.

He also wears reversible coats, hats and glasses to avoid being spotted. Depending on the job, he might use a camera-mounted pen, a pair of binoculars and a mini digital recorder to log conversations. The most high-tech item he possesses, he says, is his Sony mini videocamera for catching his subjects in the act.

Wakare-saseya (relationship break-up) agencies on the other hand use some of the most sophisticated equipment available, and were reluctant to show it to The Japan Times.

However, a camera-mounted pen that fits into the pocket of the wearer is standard fare, as is a combination camera/listening device, which is worn behind the button of a coat or dress.