Japan Supreme Court to Rule on Same-Sex Marriage Ban

Japan's Supreme Court will soon decide a historic case. The court must rule if the ban on same-sex marriage breaks the constitution. The outcome could force parliament to change the law. Japan is the only G7 country that does not recognise same-sex marriage.

What the case is about

Several same-sex couples filed lawsuits across Japan. They started the cases between 2019 and 2021. The couples argue that the current law breaks two articles of the constitution. Article 14 promises equality under the law. Article 24 protects the freedom to marry.

The government says Article 24 only covers marriage between a man and a woman. The article uses the words "both sexes". Lawyers for the couples say this reading is outdated. They point out that the article was written in 1947.

Five regional courts have ruled on the cases. Courts in Sapporo, Nagoya, Tokyo and Fukuoka called the ban unconstitutional or close to it. Only the Osaka court ruled the ban is legal. The mixed results made a Supreme Court ruling unavoidable.

How the law works now

Japanese law does not allow same-sex couples to marry. They cannot inherit from each other by default. They cannot make medical choices for a sick partner. They have no shared parental rights over children.

Some cities offer partnership certificates. Tokyo started this system in November 2022. More than 400 local governments now have similar rules. But these certificates have no legal weight. They do not give the same rights as marriage.

Foreign same-sex spouses also face problems. Japan does not give them spouse visas. They must apply for other types of permits to stay in the country.

The court process

The Supreme Court has 15 judges. Big constitutional cases go to the Grand Bench. This bench has all 15 judges. The marriage cases are expected to go there.

The court can rule in three ways. It can say the ban is constitutional. It can say the ban is unconstitutional. Or it can say the current state is "in a state of unconstitutionality". This last option is common in Japan. It signals that parliament must act, without striking down the law itself.

The court used this middle option in 2015. It told parliament to change rules about married women's surnames. Parliament did not act for years afterwards.

What public opinion shows

Surveys show growing support for same-sex marriage in Japan. A 2023 poll by news agency Kyodo found 64 percent in favour. A poll by Asahi Shimbun in 2024 found 72 percent support. Support is highest among people under 40.

Big companies also back change. More than 500 firms signed the "Business for Marriage Equality" campaign. Members include Panasonic, Sony and Nomura. They argue that the ban hurts their ability to attract foreign workers.

The ruling Liberal Democratic Party is split on the issue. Conservative members want to keep the current law. They say marriage should stay between a man and a woman. Younger LDP politicians and opposition parties want reform.

Reactions from both sides

Plaintiffs and their lawyers welcome the Supreme Court review. "We have waited years for this moment," said one plaintiff in Tokyo. Campaign group Marriage For All Japan called it a turning point.

Conservative groups oppose change. The Shinto Political League warns against rewriting Article 24. Some legal scholars also defend the current reading. They argue that any change should come from parliament, not from judges.

Prime Minister Shigeru Ishiba has said the issue needs "careful discussion". He has not promised legislation. Former prime minister Fumio Kishida said in 2023 that same-sex marriage could "change society". Critics read this as a warning, not a welcome.

What a ruling would mean

A ruling against the ban would not automatically legalise same-sex marriage. Parliament would still need to write new law. But pressure on lawmakers would grow sharply. Lower courts would also use the ruling in other cases.

A ruling in favour of the ban would close the constitutional path. Activists would then have to push for change through elections and parliament. This route has produced slow results so far.

The ruling will also affect related areas. These include adoption rights, inheritance and tax. Same-sex couples currently cannot adopt jointly. They face higher inheritance tax than married couples.

Japan in international context

More than 35 countries now allow same-sex marriage. Taiwan was the first in Asia in 2019. Thailand followed in January 2025. Nepal also recognises some same-sex marriages after a 2023 court order.

Japan stands out among rich democracies. All other G7 members recognise same-sex marriage. The United Nations Human Rights Committee criticised Japan in 2022. The committee said the country was failing to protect same-sex couples.

For more on global trends, see our overview of 7 Countries Where LGBTQ+ Rights Are Changing Fast in 2026. Court rulings on family rights have also shaped law in Europe. An Italian court recently recognised three legal parents for the first time.

What happens next

The Supreme Court has not given an exact date for its ruling. Legal experts expect a decision within months. The Grand Bench usually hears arguments before ruling.

If the court rules against the ban, parliament will face pressure to act before the next election. If parliament does nothing, more lawsuits are likely. Either way, the ruling will mark the biggest moment for LGBTQ+ rights in Japanese legal history.