At the age of 18, Mitsuhiro Matsushita already has a good idea of his ideal future. After he graduates from university a few years of work will be followed by marriage to an industrious wage earner. When children arrive it will be Mitsuhiro who stays at home looking after them, baking cakes and biscuits and living the traditional life of the Japanese housewife.

None of this would be noteworthy but for one thing. Mitsuhiro is not a conventionally minded Japanese woman, but a thoughtful, articulate and fashionably dressed young man. And far from being a marginal eccentric he is a member of a large and growing tribe of Japanese manhood that is attracting the fascinated and anxious attention of companies, academics and the mass media.

Two phrases have been coined to describe them: soshokukei danshi or “herbivorous males”, and Ojo-man – or “girly men”.

Definitions vary, but the new herbivores could be described as metrosexuals without the testosterone. Although most of them are not homosexual they have in common a disdain for the traditional accoutrements of Japanese manhood, and a taste for things formerly regarded as exclusively female. Girly men have no interest in fast cars, career success, designer labels and trophy women. Instead, they hold down humble jobs, cultivate women as friends rather than conquests and spend their free time shopping at small boutiques and pursuing in Japan what is regarded as a profoundly feminine pastime: eating cakes.

Sociologists worry about the effect on the shrinking population of a generation of men who are not interested in girls. Marketeers ponder how to sell to this new, unfamiliar demographic. Cultural commentators have produced volumes attempting to explain the phenomenon to the rest of Japan, with titles such as Love Study of Herbivores, The Men Who Wear Bras and the Women Who Don’t and Herbivorous Girly Men Are Changing Japan.

The author of the last work, Megumi Ushikubo, estimates that two thirds of men aged 20 to 34 have herbivorous tendencies. Her marketing agency advises Japanese companies on how to appeal to this new demographic — so different from the generation above who came to maturity during the “Bubble Economy” of the late Eighties and early Nineties when rising asset prices in Japan created a frenzy of conspicuous consumption.

“In the Bubble, what people valued in a car was speed and high specifications,” she says. “Herbivorous boys don’t have any interest in that. They want a car which is practical and which gives them the space to be themselves.”

The last few years have seen a range of products to cater to a broadening of tastes among Japanese men. Japanese brewers have introduced weaker beers as sales of conventional alcoholic beverages have declined. A company named WishRoom sells bras for men — designed with manly simplicity, free of lace and frills.

“In the Eighties and Ninetiess, people imagined that men should be men and women should be women,” says Shinya Yamaguchi, 23, a fashion designer. “It was all about brand goods, foreign cars and pretty girls. But now people realise they can live as they wish.”

This week, Mr Yamaguchi will launch his latest collection of skirts and lacy tops, some of them pink, and all aimed at men.

Not everyone regards the emergence of the girly men as completely positive. Masahiro Yamada, a professor of sociology at Tokyo’s Chuo University, said that it had come about as a result of economic decline: if young men were foregoing designer labels, expensive cars and hot dates at flash restaurants it was largely because, after the bursting of the Bubble and 15 years of stagnation, far fewer of them can afford these luxuries.

Japanese women, according to Professor Yamada’s research, have not caught up. Two out of five say they wish to marry a man who earns at least 6 million yen (£40,000) a year — but such men make up only 3.5 per cent of the eligible population. The result of such unrealistic female expectations is a generation of men, and women, who may never marry and have children.

About half of men aged 20 to 34, he says, are unmarried and only 20 per cent of them have girlfriends. Thirty per cent, according to Professor Yamada, have never had a girlfriend in their lives. For a country like Japan, which already has a shrinking population, this is a disaster.

“I worry that herbivorous boys are the future of Japan,” he says. “As young Japanese men become more timid and more averse to taking risks, it will affect the energy and vitality of the society.”

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