Nearly 60 female politicians in Japan, including Prime Minister Sanae Takaichi, have submitted a petition calling for more toilets in the parliament building to match their improved representation.

Although the number of women politicians rose at the last election and despite Ms Takaichi becoming the nation's first female prime minister back in October, Japanese politics remains massively male-dominated.

This is reflected by there being only one lavatory containing two cubicles near the Diet's main plenary session hall for the 73 women elected to the lower house, according to the petition.

"Before plenary sessions start, truly so many women lawmakers have to form long queues in front of the rest room," said Yasuko Komiyama from the opposition Constitutional Democratic Party.

She was speaking after submitting the cross-party appeal signed by 58 women to Yasukazu Hamada, the chair of the lower house committee on rules and administration, earlier this month.

The Diet building was finished in 1936, nearly a decade before women got the vote in December 1945 following Japan's defeat in World War II.

The entire lower house building has 12 men's toilets with 67 stalls and nine women's facilities with a total of 22 cubicles, according to the Yomiuri Shimbun newspaper.

Japan ranked 118 out of 148 this year in the World Economic Forum's Global Gender Gap Report. Women are also grossly under-represented in business and the media.

In elections, women candidates say that they often have to deal with sexist jibes, including being told that they should be at home looking after children.

In the last election in 2024, 73 women were elected to the 465-seat lower house — one has since left — up from 45 in the previous parliament. There are 74 women in the 248-seat upper house.

The government's stated target is to have women occupy at least 30 per cent of the legislative seats.

Ms Takaichi, an admirer of former British prime minister Margaret Thatcher, said before becoming premier that she wanted "Nordic" levels of gender balance in her cabinet.

But, in the end, she appointed just two other women to her 19-strong cabinet.

Ms Takaichi, 64, has said she hopes to raise awareness about women's health struggles and has spoken candidly about her own experience with menopause.

But she is still seen as socially conservative.

She opposes revising a 19th-century law requiring married couples to share the same surname, and wants the imperial family to retain male-only succession.

The increasing demand for women's toilets can be seen as a sign of progress for Japan although it also reflects the nation's failure to achieve gender equality, Ms Komiyama said.

"In a way, this symbolises how the number of female lawmakers has increased," Ms Komiyama told reporters, according to her party's website, adding that she hoped for more equality in other areas of life.

AFP