In Japan, married women who want to use their maiden names are fighting an old system in which women give up their own names on their wedding days. Japan's legal system requires couples to register their unions under a single last name, almost always the husband's.

Emi Miyashita is a 30 year-old Tokyo office worker with a live-in boyfriend. They were married, but divorced several years ago for one reason: Ms. Miyashita wanted to use her maiden name both socially and at her job in the overseas sales division of an engineering company. She likes being called by her own name and says that people around her understand her feelings: I find it inconvenient to change my name in all official and work-related documents. Some people are surprised to know about my situation, but it is not causing me any problems, she said.

For centuries, the family register has played a critical role in how Japanese society is organized. When a child is born, or when a woman marries, they are entered on a list of family members, called a family register, which entitles them to various legal rights and privileges, including inheritance.

While the law does not explicitly say that wives, and not husbands, must change their names, women do so in all but three percent of cases.

In a recent poll by the Japanese government, 42 percent of respondents said they support updating the law so that women could keep their names.

But the issue remains controversial. Almost one third of those polled opposed changing the law and 28 percent were undecided.

But the number of couples choosing to forsake marriage so that the woman can keep her name is growing. Some women are forming groups to lobby officials for change.

The pressure they are exerting appears to be working. An official council on gender equality proposed in October that the government revise the law. Five years ago, legislation to do that was drafted, but conservative members of the dominant Liberal Democratic Party killed it.

Now, greater public support and more media coverage are reviving interest in the issue. In addition, a number of lawmakers have indicated that they may back a change.

Opposition legislator Mizuho Fukushima is among the supporters: Lifestyles are now increasingly diverse so it is important to let married couples have choices between using the same or separate surnames. As a result, they will have a better partnership, said Ms. Fukushima.

Many women want to keep their names for professional reasons. More than 27 million women are employed, and many women delay marriage while they develop their careers. Ms. Fukushima and others say that changing surnames can cause a loss of identity and hinder their careers.

But critics worry that a change could hurt the society. Akiko Okamoto is a Japanese housewife who created a web site criticizing the dual-name system. She says it could lift the divorce rate: Countries such as Sweden that promote dual-name systems have a divorce rate that tops 50 percent. The dual name system could help destroy the family unit in Japan, she said.

Ms. Okamoto says a change would cause problems for children, who would be forced to choose between their mother or father's surname.

Lawmaker Fukushima thinks there would be few problems: I know many children whose parents use separate surnames, but they do not feel isolated nor do they appear to have problems, she said.

More than forty female legislators, all members of the ruling coalition, propose that a bill to change the law be soon submitted to Parliament.

Even without a new law, Japanese society appears to be slowly gravitating toward a change. Some companies and local government offices allow married women to use their maiden names at work. Just last month, all Japanese central government offices did the same, in a move officials say could help create a more equal society.