TOKYO – Six couples sued the Japanese government on March 8 over a law that requires married spouses to have the same surname.

It is the latest legal challenge against a century-old custom that many argue perpetuates inequality, as well as personal and practical harm.

Five couples filed the case in a Tokyo district court and one couple did so in Sapporo in northern Japan.

The move coincides with International Women’s Day to draw attention to the fact that the practice disproportionately affects women.

If the Supreme Court rules that the law is unconstitutional it will go on to be reviewed in Parliament. 

Previous legal challenges, including one in 2021, were dismissed by the top court.

But calls for change have grown louder as awareness grows about the professional setbacks that women suffer. That is giving the lawyers and plaintiffs behind the current lawsuit a confidence boost. 

“More and more male managers are in favour of a system where married couples can have a choice,” said lawyer Makiko Terahara, who is leading the case and worked on two similar lawsuits in the past. “Third time will be the charm.”

Japan’s powerful business lobby group Keidanren, known for its conservative stance, expressed support in February when Chairman Masakazu Tokura said at a news conference: “I personally think we should introduce a separate surname system.”

Keidanren plans to submit a recommendation letter to the government as early as the first half of 2024 on the issue. 

The single-surname system dates back to 1898 when Japan adopted laws to formalise its patriarchal family system.

Technically, a husband may adopt his wife’s surname, but in practice, it is usually the wife who changes her name.

With an increasing number of women in careers, those who continue to use their own names at work experience hassles in their day to day lives caused by the discrepancy between their legal and business names.

The name requirement also causes serious personal difficulties.

Ms Megumi Ueda, a plaintiff who works in international development, chose not to get legally married to keep her identity, but at the cost of her partner having parental rights to their child as Japan does not allow joint custody.

She said she lives in fear that if she dies it will take time for custody to be transferred.

“I think you really need a new system to make sure everyone can be happier getting married,” she said.

While surveys show broad societal support for amending the law, Japan’s conservative ruling party is often cited as a key obstacle to change. 

“Society is ready for this,” said Professor Machiko Osawa, a labour economist at Japan Women’s University.

But as “maintaining family values plays a significant role” in the Liberal Democratic Party’s (LDP) platform, she is not optimistic that things will change. 

However, even the LDP has been cognisant of growing support for changing the law and adjusted its position over time.

In 2019 the government allowed people to list both their own and married names on some identification documents. 

“It’s clear that political attempts to promote the use of business names are not working,” said Emeritus Professor Shuhei Ninomiya, who specialises in family law at Ritsumeikan University.

For Ms Ueda, changing the law is something she believes must end with her generation after decades of waiting. 

“When I first became interested in this topic I was in junior high, and I thought the law would change by the time I grew up,” she said. “But now I’m in my 40s and nothing has. We can’t keep passing this on to the younger generation.” BLOOMBERG