TOKYO — The paperwork never ends for Yoshiko Nishimasa.

There are the meticulous logs she must fill out every day, not to mention the pages of work she carefully checks and approves with a personalized stamp. She even keeps daily records of conversations, activities and meals.

But none of this bookkeeping is for her job as a marketing professional. It’s all for her children’s preschool — before she can even head to the office.

Like so many working mothers in Japan, Ms. Nishimasa, 38, is swamped by onerous, bureaucratic tasks that have nothing to do with her profession but constrain her participation in the work force at a time when the country says it desperately needs more from women like her.

Japan’s prime minister, Shinzo Abe, has an explicit goal of energizing his nation’s puttering economy by elevating women in the labor force, an initiative catchily referred to as “womenomics.”

At the World Economic Forum in Davos, Switzerland, in January, Mr. Abe boasted that 67 percent of women were working in Japan, an all-time high and “higher than, say, in the United States.”

But many of those women are stuck in limited roles in the workplace, and one of the biggest hindrances to their ambitions — and the nation’s as a whole — is the disproportionate burden women shoulder at home.

In fact, men in Japan do fewer hours of household chores and child care than in any of the world’s wealthiest nations.

According to an analysis of government data by Noriko O. Tsuya, an economics professor at Keio University in Tokyo, women who work more than 49 hours a week typically do close to 25 hours of housework a week. Their husbands do an average of less than five.

Consider Ms. Nishimasa’s daily routine. The preschool her two youngest children attend requires the family to keep daily journals recording their temperatures and what they eat twice a day, along with descriptions of their moods, sleeping hours and playtime. On top of that, her 8-year-old son’s elementary school and after-school tutoring class require that a parent personally signs off on every homework assignment.

The paperwork, of course, is just the beginning. There is cooking, cleaning and laundry, often at a scale that far exceeds what most Westerners do. Cooking a typical Japanese dinner often involves preparing multiple small dishes. Packed lunches can be works of art. Dishwashers are not yet ubiquitous. And as for laundry, few families own dryers big enough for large loads, so wet clothes are generally hoisted on clotheslines.

She does the vast majority of it all.

Her husband, a management consultant, often stays late at the office or goes out drinking with clients — which are also deeply entrenched expectations in Japan, particularly for men.

But Japan’s economy needs educated women like Ms. Nishimasa to work to their full potential. After World War II, as the nation entered a period of rapid economic growth, Japanese women typically quit work when they married or gave birth, taking care of the home while their husbands worked punishingly long hours to power Japan Inc.’s industrial expansion.

In the late 1970s, married women slowly started to enter the work force. Then, when Japan’s stock and property bubbles popped in the early 1990s, large numbers of them went back to work to keep their families afloat financially.

After that, Japan, once the economic powerhouse of Asia, struggled to lift itself from a protracted period of stagnation. It was overtaken by China as the world’s second-largest economy in 2011, and Mr. Abe has staked much of his reputation on returning the economy to steady growth and keeping it from becoming a global afterthought.

But close to half of working women are employed part time, and more than half are on temporary contracts, reinforcing a large pay gap between men and women.

According to the Organization for Economic Cooperation and Development, women in Japan represent fewer than 1 percent of management positions, compared with an average of 4.6 percent among the world’s most developed nations.

Kathy Matsui, a Goldman Sachs strategist who wrote influential papers that Mr. Abe relied on when formulating his “womenomics” policy, said that raising women’s employment rates to the same level as men’s could increase the country’s economic output by more than 10 percent.

But the boost to the Japanese economy would be much larger if women could pursue higher-level careers and were appropriately paid, Ms. Matsui added.

“How do we make that happen?” she said.

At the moment, Japanese women often face a double-edged sword.

Like many Japanese companies, Ms. Nishimasa’s employer accommodates her towering domestic responsibilities. Until her youngest child, now 2, enters second grade, she can work a shortened seven-hour day, albeit for 30 percent lower pay. She is never asked to do the kind of overtime she regularly put in before her children were born, when she was often at the office until 10 p.m. or later.

“When I asked why,” she said, “my boss said my output was lower because I work fewer hours.”

After Ms. Nishimasa graduated from a top university in Tokyo, she worked for a textbook publisher as a sales associate. With a sunny disposition and her ease at striking up conversations, she quickly excelled.

She married four years later. Much to her shock, the company automatically converted her employment status to part-time, she said.

“My boss started saying, ‘You are not long for this job because you’re probably just going to go off and have kids, right?’” she recalled.

She looked for another job, but prospective employers said, “You probably can’t work late, right?” or “Does your husband understand how busy you will be?”

The publisher where she landed did not ask her marital status. But the hours were intense, and when she did get pregnant, at 29, she did not slow down, often remaining in the office until midnight. She miscarried in the final month of her pregnancy.

She got pregnant again, yet continued working long hours, anxious not to appear to be shirking her share of the work. When she left at 10 p.m., she recalled, “I was the earliest one leaving and I would have to beg my colleagues for forgiveness.”

The juggle took a toll. One rainy morning, Ms. Nishimasa wrestled with the children while rushing down the stairs with two big bags of clothes, towels, washcloths and water bottles required by their day care. In her hurry, she slipped and fell, breaking a leg.

“I was pushing myself too much,” she said.

After the accident, Mr. Nishimasa came home early in the evenings for two months and agreed to drop off the children at day care on his way to work, one of the few tasks he still handles for the family.

Now, Mr. Nishimasa is back to working long hours to keep up with their mortgage payments. He rarely makes it home before 10 p.m., and is often out much later. On Saturdays, he sleeps in while his wife shuttles the three children to piano lessons or sports activities before he wakes up.

Since Ms. Nishimasa broke her leg, her husband has never left work in the middle of the day. If a child gets sick or hurt, or if school ends early, she gets the call every time.

Ms. Nishimasa tries getting to work early once a week. She helps get the children dressed, makes breakfast and then heads to the office to snag some quiet time before most of her colleagues arrive.

Gender Equality a Distant Dream

Just over half of Japanese mothers go back to work after the birth of their first child. But they often have part-time jobs while their husbands continue to work brutal hours, contributing to a phenomenon known as “karoshi,” or “death from overwork.”

Some experts argue that Japan’s culture of overwork is unnecessary, leading to inefficiencies and low productivity. If everyone worked fewer hours, women might be able to catch up and Japanese society as a whole would benefit, they contend.

Despite some efforts to modify the work culture, excessive hours remain the norm, helping explain why men contribute so little to housework or child care: They simply do not have much time.

“If the work day could be shortened in Japan, I think a younger generation of men would do more as fathers,” said Margarita Estevez-Abe, associate professor of political science at Syracuse University.

Entrenched cultural expectations are another obstacle.

Last year, when Daiwa House, a homebuilder, conducted a survey of 300 working couples, most of the respondents said that women completed close to 90 percent of the chores at home, many of them unacknowledged by their husbands. The results went viral on social media under the hashtag “namonaki kaji,” which roughly translates as “invisible house chores.”

“The awareness of men is still so low,” said Kazuko Yoshida, 38, a graphic designer and mother of two young children in Tokyo. “My husband does not have a gender equality concept.”

Ms. Yoshida drops off and picks up the children every day, and cooks, cleans, bathes and puts them to bed each night. When the preschool asked parents to make a handmade doll for each child, Ms. Yoshida stayed up nights sewing them.

“I work so hard,” he said. “I come home late at night and am exhausted in the morning.”

As Ms. Yoshida left the office to pick up her children, she sat on the platform at the train station and let two trains go by before climbing into a packed car to head to the day care center. It was her only break all day.

Multitasking Moms

On a Friday afternoon, Ms. Nishimasa dashed out of the office to pick up her daughter Mei, 5, and youngest son, Haruki, 2, heading straight for the child-size mattresses stacked in their preschool.

She grabbed their nap pads, stripped off the sheets and blankets and put on a fresh set she had washed at home. She planned to come back with even more sheets the next day — a Saturday — to make the scramble of the workweek a little more manageable.

Then she retrieved Mei’s indoor shoes — they also needed washing — before a teacher handed her some construction paper: a weekend homework assignment to make a flag.

Outside, with the wind gusting, Ms. Nishimasa loaded both children onto a bicycle, shoved a teddy bear into a bag of laundry, hiked up her skirt and climbed on for the ride home.

They arrived just after 6 p.m. Ten minutes later, her oldest son, Kazuaki, 8, breezed in from an after-school program, dumping his backpack and snatching candy from Haruki’s hands, prompting the toddler to bleat in protest.

Ms. Nishimasa strapped on an apron and began chopping, fixing an array of dishes: marinated cucumber and tomato salad, mustard greens with sesame seeds, steamed squash and hot bowls of miso soup and rice.

The children, indifferent to the spread, gazed at cartoons. Ms. Nishimasa snatched bites of dinner while loading the washing machine and drawing a bath. She checked Kazuaki’s homework for the corrections ordered by his teacher, rinsed the dishes and put the leftovers away.

One after another, the children popped in and out of the bath. She tried, unsuccessfully, to coax them to bed. It was after 9 p.m., but she made herself a cup of coffee, hoping she might actually get to drink it before it got cold.

Just before 10 p.m., her phone buzzed with a text. It was not her husband, who was out drinking with clients. It was another mother, asking for a breakfast play date the next morning, while their husbands would be sleeping in.