Japanese Prime Minister Yasuo Fukuda, who is 71 years old, with his wife Kiyoko who is 63. (AFP)

Salaried men — the black-suited corporate warriors who work long hours, spend long evenings drinking with cronies and stumble home late to long-suffering wives — have danger waiting for them as they near retirement.

Divorce. A change in Japanese law this year allows a wife who is filing for divorce to claim as much as half her husband’s company pension.

When the new law went into effect in April, divorce filings across Japan spiked 6.1 per cent. Many more split-ups are in the pipeline, marriage counsellors predict. They say wives — hearts gone cold after decades of marital neglect — are using calculators to ponder pension tables, the new law and the big D.

Skittishly aware of the trouble they are in, 18 salarymen, many of them nearing retirement, gathered at a restaurant here recently for beer, boiled pork and marital triage.

The evening began with a defiantly defeatist toast. Husbands reminded themselves of what their organisation — the improbably named National Chauvinistic Husbands Association — preaches as a sound strategy for arguing with one’s wife.

“I can’t win. I won’t win. I don’t want to win,” they bellowed in unison, before tippling from tall schooners of draft beer. The pork was scrumptious and the mood jolly, but throughout the dinner meeting there was an undertow of not-too-distant domestic disaster.

“The fact that a wife can now get 50 per cent has ignited guys to think about their fragile marriages,” said Shuichi Amano, 55, founder of the association and a magazine publisher in this city of 1.3 million in western Japan.

The word chauvinist in the group’s name, Amano says, is not intended to refer to bossy men. Instead, it invokes the original meaning of the Japanese word that today translates as chauvinist. Men near the end of their corporate lives, he said, are especially edgy. “To be divorced is the equivalent of being declared dead — because we can’t take care of ourselves,” Amano said.

When his wife told him eight years ago that she was “99 per cent” certain she was going to dump him, Amano said, the only things he then knew how to do in the kitchen were to fry eggs and pour boiled water over noodles.

Since then, in addition to learning how to listen and talk to a wife he had ignored for two decades, Amano said, he has learned how to take out the trash and clean the house

The age of first marriage is being pushed back in Japan. Between 1962 and 2006, the average age at which a woman married for the first time slid from 24 to 28.

But for well-educated (and presumably well-informed) young women in Japan, marriage is fast becoming a rarity. In 1980, about three-quarters of Japan's college-educated women were married by age 29. Now, seven out of 10 are single at that age. In the past 20 years, the percentage of women in this category who do not want to marry at all has doubled.