The moment at which adult nappy sales overtook baby nappy sales in Japan happened, according to industry figures widely reported at the time, in 2011. The tipping point was documented in trade press coverage of the domestic incontinence-products market and has been cited consistently since by Reuters, Bloomberg, and the Japanese business press, but a specific public filing pinning the exact quarter and product-level unit numbers to a single manufacturer’s disclosure does not appear to be available in the English-language record. 444
What is clear from the trade coverage is that Unicharm, the country’s largest producer of both baby and adult nappies, was reporting adult unit sales ahead of baby unit sales in the domestic Japanese market from around that year onward, and that the company’s public commentary in the years since has consistently emphasised the adult segment as its primary Japanese growth business. Unicharm has not exited the baby nappy market. It has continued to make and sell baby nappies both in Japan and internationally, and its overseas baby-nappy business has grown substantially during the same period its Japanese adult business has expanded.
The full exit came from a different company. In March 2024, according to Fortune magazine’s reporting compiled from Bloomberg and BBC coverage of Oji Holdings’ own announcement, the major paper manufacturer Oji Holdings said its subsidiary Oji Nepia would cease baby nappy production in Japan entirely from September 2024. Oji Nepia had been manufacturing approximately 400 million infant nappies per year at that point, down from a peak of 700 million per year in 2001. The company will continue to make adult nappies for the domestic market. A large Japanese consumer paper manufacturer had, for the first time, walked away from making infant nappies for its own home country because demand from young families had fallen too far to keep the production lines profitable.
There was no major protest. The announcement was covered as a business decision. And it was consistent with what the underlying demographic numbers had been signalling for years.
The numbers behind the story
According to demographic statistics released by Japan’s Ministry of Health, Labor and Welfare and compiled by Nippon.com in early 2025, the number of births recorded in Japan during 2024 fell below 700,000 for the first time since the country began collecting national demographic data in 1899. The final figure was 686,061 births, down 5.7 per cent from the previous year, and marking the ninth consecutive year of decline. The total fertility rate, which is the number of children an average woman is expected to have across her lifetime, fell to 1.15. The fertility rate required simply to replace the existing population, absent any migration, is 2.1.
The number of deaths recorded in the same year was 1,605,298, a postwar high. Japanese people, in 2024, were dying at approximately 2.34 times the rate at which Japanese babies were being born. The natural decrease in the Japanese national population, meaning the number of deaths minus the number of births, came to 919,237. The country lost, in a single calendar year, most of the population of a large European capital city.
The overall population of Japan, as of April 2025, sat at 123.4 million. Roughly thirty per cent of that population was aged 65 or older, a figure that on the World Bank’s international comparisons places Japan second only to Monaco in the proportion of its citizens who are elderly. The working-age share, meaning the group aged 15 to 64 who ordinarily fund a country’s tax base and social welfare system, sat at approximately 60 per cent, and continues to shrink each year as the boundary between the working-age population and the retired population moves upward faster than young workers can be added at the bottom.
Prime Minister Shigeru Ishiba has publicly described the trajectory as a quiet emergency. On the current mathematical trajectory, the Japanese population is projected to fall to approximately 87 million by 2070, a reduction of roughly thirty per cent from its current level.
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Why it is happening
The demographic mathematics is straightforward. Births have to exceed deaths, on average, for a population to grow. In Japan they have not done so for eighteen consecutive years. The interesting question is why.
The single largest contributor is the delayed and reduced formation of new households by young Japanese adults. According to Newsweek’s reporting in August 2025 on the Ministry of Internal Affairs and Communications’ latest statistical release, the number of Japanese people aged 15 to 64 has now fallen below sixty per cent of the total population, while the proportion aged 65 or older has climbed above thirty per cent. Younger Japanese adults are marrying later, having fewer children when they do marry, and in a growing proportion of cases not marrying or having children at all.
The reasons cluster around a small number of well-documented pressures. Housing costs in Japan’s major cities, particularly Tokyo, have remained genuinely high relative to real wages for the past two decades. Employment conditions, particularly for younger workers, have shifted away from the stable lifetime employment that supported the country’s postwar family formation and toward more precarious contract-based work. The dominant Japanese workplace culture continues to demand hours and levels of commitment from working parents, and particularly working fathers, that many prospective couples describe as incompatible with raising children. And the disproportionate weight of unpaid domestic labour, including both childcare and elder care, has continued to fall on Japanese women, who now face the compound choice between a demanding career, primary responsibility for raising children, and eventually primary responsibility for caring for ageing parents.
The Tokyo Metropolitan fertility rate, as of 2024, was 0.96. Below one child per woman. Tokyo is producing children at a rate that would, absent any migration, halve the population of the capital every generation.
What the pattern points at
The Japanese case matters not because Japan is uniquely troubled, but because Japan is arriving at a demographic future that most developed countries are also heading toward. South Korea, whose fertility rate in 2024 sat at 0.75, is projected to reach the same demographic threshold Japan crossed in the mid-2000s within the next decade. Italy, Spain, Germany, and much of Eastern Europe are following similar trajectories at slightly slower rates. China, whose one-child policy compressed the same demographic transition into a shorter timeframe than any comparable country has ever experienced, is now producing fewer than ten million babies per year against a total population of 1.4 billion, and passed its own natural population peak in 2022.
What Japan is demonstrating, on the ground, is the set of practical consequences that follow when a modern developed economy fails to maintain the demographic replacement rate for long enough. Those consequences do not arrive dramatically. They arrive as small closures. A local school without enough students to continue operating. A rural train line no longer commercially viable. A paper manufacturer announcing that it will no longer make baby nappies for its own domestic market. A supermarket in a suburban town that stocks more mobility aids than schoolbags. A national statistical release each year showing that another approximately one million Japanese people have died and not been replaced by births.
The nappy statistic, which has been circulating in international coverage of Japan since roughly 2013, is one of the few markers of the whole trajectory that lands intuitively enough for readers outside Japan to grasp what is being described. It sits close to ordinary domestic experience. It is not an abstraction. It is what a country ageing faster than it can replace itself, on any metric a supermarket buyer would recognise, ends up looking like at the level of the shelf. What Japan is showing the rest of the developed world is what that shelf looks like ten and twenty years into the process, and what the numbers underneath it turn into by then.
Kiran Athar is a writer, not a demographer or an economist. This piece draws on official Japanese Ministry of Health, Labor and Welfare demographic releases as compiled by Nippon.com, industry reporting from Fortune, Bloomberg and the BBC, and follow-on coverage by Newsweek of the Japanese Ministry of Internal Affairs and Communications’ 2025 statistical release.
