Japan's Supreme Court has ruled a workplace's restriction on which bathroom a transgender employee could use was not legal.

The case involves a worker at Japan's Ministry of Economy, Trade and Industry. The woman, who identifies as transgender, filed a suit in 2015 after she was banned by her government office from using certain women's restrooms.

A district court found those restrictions to be illegal. But the Tokyo High Court later overturned that ruling.

On Tuesday, Japan's top court ruled against the bathroom restriction.

It says the workplace caused significant inconvenience for the plaintiff while placing excessive priority on the feelings of other employees.

It's the first time Japan's Supreme Court has ruled on a case regarding LGBTQ employees in the workplace.

The plaintiff says it could have wide-ranging impacts on Japanese companies and public agencies.

The plaintiff also said: "This is a Supreme Court ruling for people who are transgender or experience gender dysphoria, but the judges' opinions could also apply in other human rights issues where discrimination still happens.

Japan's top government spokesperson says officials will examine the ruling and respond accordingly.

Chief Cabinet Secretary Matsuno Hirokazu said: "We will do our best to create a society where diversity and human rights are respected, and people of all identities, including members of sexual minorities and the majority, can enjoy full lives.

It comes after Japan's Diet passed a law to promote understanding of the LGBTQ community last month.