Shinjiro Koizumi’s break from his job as Japan’s environment minister began on Friday when his wife, the TV personality Christel Takigawa, gave birth to the couple’s first child.

While the daytime TV shows cooed over the new addition to the celebrity couple’s family, his decision to become the first cabinet minister to take time away from work to be with his wife and son has raised hopes of change in a country where a tiny fraction of men exercise their right to paternity leave.

Japan’s leave provision is among the most generous in the world, with new fathers permitted to spend up to a year off work, albeit on reduced incomes. But very few exercise their right, citing the pressure of their job, money concerns and a work culture that expects them to put work above family commitments.

Just 6% of Japanese men took paternity leave in the year to March 2019, according to government figures – well below the goal of 13% by this year. Of those men who take any leave, more than 70% are away for less than a fortnight. That contrasts with countries such as Sweden, where almost 90% of men take paternity leave.

A Kyugetsu employee displays hagoita – ornamental wooden rackets – decorated with images of Shinjiro Koizumi and Christel Takigawa (R), Emperor Naruhito and Empress Masako (C) and Ryota Yamasato and Yu Aoi (L). Photograph: Aflo/Rex/Shutterstock

In the UK about 90% of fathers take some sort of formal leave around the time of their child’s birth, though take-up for the government’s shared parental leave scheme – introduced in 2015 in an attempt to give fathers more time to bond with their babies, and to ease expectations on mothers – has been very poor, as low as 2%.

Koizumi said: “Honestly, I had to think over and over how I should take time off for child-rearing, or take paternity leave, while fulfilling my public duty as environment minister. Unless we change the atmosphere, government employees presumably won’t start taking paternity leave. I hope there will be a day when lawmakers’ paternity leave is no longer news.”

Critics said Koizumi, who has been touted as a future prime minister, was seeking publicity and should focus on his ministerial duties. Polls by TV networks, however, showed a majority of people backed his decision.

The popular politician confirmed this week that he would stay at home, but only for a total of two weeks, spread out over three months. In addition, he will “telecommute” and work his days off around parliamentary sessions and cabinet meetings.

The attitude of not wanting to be a nuisance is deeply embedded in the Japanese psyche, especially in the workplace. Yuko Kawanishi

Despite taking only a fraction of the leave he is entitled to, Koizumi’s move has raised hopes that more new fathers will be emboldened to stay home during their children’s formative days.

Yuko Kawanishi, a sociologist at JF Oberlin University in Tokyo, said: “Taking just two weeks off is a bit of a joke, but it’s an important gesture by someone with Koizumi’s status and popularity. It sends a positive message to the rest of Japanese society.”

Kawanishi expects firms to take a more flexible approach as older men in management positions are replaced by younger colleagues. “Some companies are going in the right direction because they realise how important having a good attitude to the work-life balance is to their corporate image,” she said.

Pressure on Japanese men to continue performing their traditional role as breadwinner after becoming fathers threatens to frustrate government attempts to encourage more women to enter the workforce and to raise the country’s low birthrate.

Campaigners applauded Koizumi’s rare challenge to Japan’s conservative attitude towards gender roles, particularly in its male-dominated corporate culture.

“A leader’s decision can change the entire social atmosphere and serve as a trigger for more men to take childcare leave,” Tetsuya Ando, head of the nonprofit group Fathering Japan, told Kyodo news agency, adding that he would have preferred the minister to take more time off.

The message appears to be getting through, with the chief cabinet secretary, Yoshihide Suga, among those voicing support for Koizumi.

Very few new fathers in Japan exercise their right to paternity leave. Photograph: YDL/Getty Images

As Japan grapples with an ageing population and dwindling birthrate, the government is trying to normalise the idea of paternity leave, announcing last month that it would allow civil servants to take more than a month off.

The alleged mistreatment of men who take leave gave rise to the phrase patahara, short for paternity harassment, which men who take time away from work say they experience when they return. This plight was highlighted last year when an employee of the Japanese sports equipment maker Asics sued his employer, claiming he had been unfairly treated after taking paternity leave.

Kawanishi said: “If you’re going to be away for several months then a lot of Japanese people worry that they will cause trouble to their colleagues. That attitude – of not wanting to be a nuisance – is deeply embedded in the Japanese psyche, especially in the workplace.”

Unless someone like Koizumi shows the way, nothing will ever change. Koji Shidane

Glen Wood took legal action in 2018 against his former employer, the financial services company Mitsubishi UFJ Morgan Stanley, for allegedly forcing him out of his job after he took paternity leave. The Canadian former brokerage manager had taken five months off to be with his son, who was in intensive care, but was allegedly harassed when he returned to work. The company has denied the allegations.

Koji Shidane, a company employee in his late 40s, said he could not have contemplated taking paternity leave when his two daughters were born two decades ago. “It’s a good idea,” he said of Koizumi’s decision. “It’s becoming the norm in other countries so it’s about time Japan caught up. Bringing up children is a man’s job too.”

Shidane said, however, that few ordinary “salarymen” felt able to follow Koizumi’s lead. “Japan hasn’t got the balance right yet. Too many people still think that the husband must go out to work and leave childcare to his wife,” he said. “It all depends on what kind of company you work for. A lot of men are worried about what their colleagues will think of them if they take time off. But unless someone like Koizumi shows the way, nothing will ever change.”