One result is a new underclass of young men who can't or won't join the full-time working world and who are a stark counterpoint to Japan's long-running image as a country bursting with industrious salarymen. "We used to believe everyone was equal," said Noki Futagami, the founder of New Start. "But the gap is growing. I suspect there will be a bipolarization of this society. There will be the group of people who can be in the global world. And then there will be others, like the hikikomori. The ones who cannot be in that world."

In the mid-1980's, young men began showing up at Dr. Tamaki Saito's office who were lethargic and uncommunicative and spent most of their days in their rooms. "I didn't have a name for it," Saito told me one Friday evening at Sofukai Sasaki Hospital outside Tokyo, where he's the medical director. Saito is soft-spoken with sleepy eyes and thick black hair that he brushes off his forehead as he talks. For the last decade he has been Japan's reigning expert on hikikomori, and his office shelves are filled with books he has written on the subject, including "How to Rescue Your Child From

Hikikomori."

"Initially, I diagnosed it as a type of depression or personality disorder, or schizophrenia," Saito went on to say. But as he treated an increasing number of patients with similar symptoms, he used the term hikikomori for the problem. Soon after, the media latched on to the phenomenon, dubbing the shut-ins "the lost generation," "the missing million" and "the ultimate in social parasitism" and making hikikomori the focus of dozens of books, magazine articles and films -- including a documentary, "Home," in which a filmmaker tracked the life of his shut-in brother. At the same time, hikikomori were making headlines for sensationalistic crimes, like the kidnapping of a 9-year-old girl by a shut-in who hid her in his room for almost a decade.

In reality, though, most hikikomori are too trapped by inertia to leave their houses, much less plot violent schemes. Instead, they are more likely to suffer depression or obsessive-compulsive behaviors. In some cases these psychological problems lead to hikikomori. But often they are symptoms -- a consequence of spending months cooped up inside their rooms and inside their heads. One hikikomori took showers several hours a day and wore gloves as thick as an astronaut's to ward off germs (he eventually joined a halfway program, threw away the gloves and got a job), while another scrubbed the tiles in his family's shower for hours at a time. "Our water bills were 10 times what they'd normally be," his brother told me. "It's as if he was trying to clean the dirt in his mind and his heart."

Saito, who has treated more than 1,000 hikikomori patients, views the problem as largely a family and social disease, caused in part by the interdependence of Japanese parents and children and the pressure on boys, eldest sons in particular, to excel in academics and the corporate world. Hikikomori often describe years of rote classroom learning followed by afternoons and evenings of intense cram school to prepare them for high-school or university entrance exams. Today's parents are more demanding because Japan's declining birth rate means they have fewer children on whom to push their hopes, says Mariko Fujiwara, director of research at the Hakuhodo Institute of Life and Living in Tokyo. If a kid doesn't follow a set path to an elite university and a top corporation, many parents -- and by extension their children -- view it as a failure. "After World War II," Fujiwara told me, "Japanese only knew a certain kind of salaryman future, and now they lack the imagination and the creativity to think about the world in a new way."

Those post-World War II salarymen who did work so tirelessly were at least rewarded with the security of lifetime employment. "It was simple in my youth -- you went to high school, then to the University of Tokyo," says Noki Futagami of New Start, referring to Japan's most prestigious university. "And then you got a job in a major corporation. That's where you grew up. The corporation took care of you for the rest of your life." Now in its place is a leaner global economy that demands the kinds of skills -- independent thinking, communication, entrepreneurship -- that many parents and schools don't teach. Boys have spent their young lives being educated for a work system that has shriveled, leaving many feeling inadequate and stuck.

Many hikikomori also describe miserable school years when they didn't, or couldn't, conform to the norm. They were bullied for being too fat or too shy or even for being better than everyone else at sports or music. As the Japanese saying goes, "The nail that sticks out gets hammered in." One hikikomori was a victim of bullying in fifth grade because he excelled in baseball without having played as long as his teammates. His father admitted that he did nothing to help him. "We told him to handle it himself. We thought he was stronger than he was." Fujiwara says that urban Japanese parents lead increasingly isolated lives -- removed from the extended family and tight-knit communities of previous generations -- and simply don't know how to teach their children to communicate and negotiate relationships with peers.