Ryoma Igarashi likes going for long drives through the mountains, taking photographs of Buddhist temples and exploring old neighborhoods. He’s just taken up gardening, growing radishes in a planter in his apartment. Until recently, Igarashi, a 27-year-old Japanese television presenter, would have been considered effeminate, even gay. Japanese men have long been expected to live like characters on Mad Men, chasing secretaries, drinking with the boys, and splurging on watches, golf, and new cars.

Today, Igarashi has a new identity (and plenty of company among young Japanese men) as one of the soushoku danshi—literally translated, “grass-eating boys.” Named for their lack of interest in sex and their preference for quieter, less competitive lives, Japan’s “herbivores” are provoking a national debate about how the country’s economic stagnation since the early 1990s has altered men’s behavior.

Newspapers, magazines, and television shows are newly fixated on the herbivores. “Have men gotten weaker?” was one theme of a recent TV talk show. “Herbivores Aren’t So Bad” is the title of a regular column on the Japanese Web site NB Online.

In this age of bromance and metrosexuals, why all the fuss? The short answer is that grass-eating men are alarming because they are the nexus between two of the biggest challenges facing Japanese society: the declining birth rate and anemic consumption. Herbivores represent an unspoken rebellion against many of the masculine, materialist values associated with Japan’s 1980s bubble economy. Media Shakers, a consulting company that is a subsidiary of Dentsu, the country’s largest advertising agency, estimates that 60 percent of men in their early 20s and at least 42 percent of men aged 23 to 34 consider themselves grass-eating men. Partner Agent, a Japanese dating agency, found in a survey that 61 percent of unmarried men in their 30s identified themselves as herbivores. Of the 1,000 single men in their 20s and 30s polled by Lifenet, a Japanese life-insurance company, 75 percent described themselves as grass-eating men.

Japanese companies are worried that herbivorous boys aren’t the status-conscious consumers their parents once were. They love to putter around the house. According to Media Shakers’ research, they are more likely to want to spend time by themselves or with close friends, more likely to shop for things to decorate their homes, and more likely to buy little luxuries than big-ticket items. They prefer vacationing in Japan to venturing abroad. They’re often close to their mothers and have female friends, but they’re in no rush to get married themselves, according to Maki Fukasawa, the Japanese editor and columnist who coined the term in NB Online in 2006.

Grass-eating boys’ commitment phobia is not the only thing that’s worrying Japanese women. Unlike earlier generations of Japanese men, they prefer not to make the first move, they like to split the bill, and they’re not particularly motivated by sex. “I spent the night at one guy’s house, and nothing happened—we just went to sleep!” moaned one incredulous woman on a TV program devoted to herbivores. “It’s like something’s missing with them,” said Yoko Yatsu, a 34-year-old housewife, in an interview. “If they were more normal, they’d be more interested in women. They’d at least want to talk to women.”

Shigeru Sakai of Media Shakers suggests that grass-eating men don’t pursue women because they are bad at expressing themselves. He attributes their poor communication skills to the fact that many grew up without siblings in households where both parents worked. “Because they had TVs, stereos and game consoles in their bedrooms, it became more common for them to shut themselves in their rooms when they got home and communicate less with their families, which left them with poor communication skills,” he wrote in an e-mail. (Japan has rarely needed its men to have sex as much as it does now. Low birth rates, combined with a lack of immigration, have caused the country’s population to shrink every year since 2005.)

It may be that Japan’s efforts to make the workplace more egalitarian planted the seeds for the grass-eating boys, says Fukasawa. In the wake of Japan’s 1985 Equal Employment Opportunity Law, women assumed greater responsibility at work, and the balance of power between the sexes began to shift. Though there are still significant barriers to career advancement for women, a new breed of female executive who could party almost as hard as her male colleagues emerged. Office lechery, which had been socially acceptable, became stigmatized as seku hara, or sexual harassment.

But it was the bursting of Japan’s bubble in the early 1990s, coupled with this shift in the social landscape, that made the old model of Japanese manhood unsustainable. Before the bubble collapsed, Japanese companies offered jobs for life. Salarymen who knew exactly where their next paycheck was coming from were more confident buying a Tiffany necklace or an expensive French dinner for their girlfriend. Now, nearly 40 percent of Japanese work in nonstaff positions with much less job security.

“When the economy was good, Japanese men had only one lifestyle choice: They joined a company after they graduated from college, got married, bought a car, and regularly replaced it with a new one,” says Fukasawa. “Men today simply can’t live that stereotypical ‘happy’ life.”

Yoto Hosho, a 22-year-old college dropout who considers himself and most of his friends herbivores, believes the term describes a diverse group of men who have no desire to live up to traditional social expectations in their relationships with women, their jobs, or anything else. “We don’t care at all what people think about how we live,” he says.

Many of Hosho’s friends spend so much time playing computer games that they prefer the company of cyber women to the real thing. And the Internet, he says, has helped make alternative lifestyles more acceptable. Hosho believes that the lines between men and women in his generation have blurred. He points to the popularity of “boys love,” a genre of manga and novels written for women about romantic relationships between men that has spawned its own line of videos, computer games, magazines, and cafes where women dress as men.

Fukasawa contends that while some grass-eating men may be gay, many are not. Nor are they metrosexuals. Rather, their behavior reflects a rejection of both the traditional Japanese definition of masculinity and what she calls the West’s “commercialization” of relationships, under which men needed to be macho and purchase products to win a woman’s affection. Some Western concepts, like going to dinner parties as a couple, never fit easily into Japanese culture, she says. Others never even made it into the language—the term “ladies first,” for instance, is usually said in English in Japan. During Japan’s bubble economy, “Japanese people had to live according to both Western standards and Japanese standards,” says Fukasawa. “That trend has run its course.”

Japanese women are not taking the herbivores’ indifference lightly. In response to the herbivorous boys’ tepidity, “carnivorous girls” are taking matters into their own hands, pursuing men more aggressively. Also known as “hunters,” these women could be seen as Japan’s version of America’s cougars.

While many Japanese women might disagree, Fukasawa sees grass-eating boys as a positive development for Japanese society. She notes that before World War II, herbivores were more common: Novelists such as Osamu Dazai and Soseki Natsume would have been considered grass-eating boys. But in the postwar economic boom, men became increasingly macho, increasingly hungry for products to mark their personal economic progress. Young Japanese men today are choosing to have less to prove.