Articles about Japan’s population drew major attention in Korea as well.
Most headlines said that 1억2000만 people—120 million—had been breached.
But another line in the release is what really catches the eye.
3-line summary
1. Japan’s Japanese-national population fell below 1억2000만 for the first time in 42 years.
2. It has declined for 17 consecutive years, while the foreign population exceeded 400만 for the first time.
3. Over the same period, South Korea’s number of births has risen for a second consecutive year.
Figures released on July 29
These are the population figures as of January 1, 2026, released by Japan’s Ministry of Internal Affairs and Communications based on resident registration.
| Population | Year-on-year change | |
|---|---|---|
| Japanese nationals | 1억 1973만 6483명 (119,736,483 people) | −91만 6744명 (−0.76%) |
| Foreign nationals | 403만 1159명 (4,031,159 people) | +35만 3696명 (+9.62%) |
| Total | 1억 2376만 7642명 (123,767,642 people) | −56만 3048명 |
The Japanese-national population fell below 1억2000만 people for the first time in 42 years, since 1984. This was not its first decline—it has now fallen for 17 consecutive years.
Two lines absent from the headlines
The same release includes these figures.
- Babies born: 67만 467명 (670,467) — the lowest ever
- Deaths: 159만 3475명 (1,593,475)
The difference is 92만 3008명 (923,008). Without immigration, this means the population would shrink by this amount each year.
The ratio makes the situation clearer. For every one person born, 2.4 people die. More than the rounded figure of 1억2000만, this ratio explains Japan today.
Only Tokyo grew
Among Japan’s 47 prefectures, Tokyo was the only place where the Japanese-national population increased. The other 46 all declined.
This means population decline is not spreading evenly across the country. It is proceeding by drawing people into one place while leaving the rest empty. Looking only at the national average obscures this structure.
Tokyo also has a different share of foreign residents. The national average is 3.26%, while Tokyo’s is 5.57%.
Why the total population declined less
Looking again at the table, there is something unusual. The Japanese-national population fell by 91만 people, but the total population fell by only 56만.
The difference is foreign nationals. The foreign population, which grew by 35만, offset more than one-third of the decline. The number of people arriving from overseas reached 72만 988명 (720,988), the highest ever.
One point is worth noting here. When news reports refer to “Japan’s population,” the figure differs by 35만 people depending on whether it means the Japanese-national population or the total population. The two statistics tell different stories.
Then what about South Korea?
Let us place South Korea’s figures alongside them. These are preliminary 2025 figures released by Statistics Korea.
| 2025 | Year-on-year change | |
|---|---|---|
| Births | 25만 4,500명 (254,500 people) | +1만 6,100명 (+6.8%) |
| Deaths | 36만 3,400명 (363,400 people) | +4,800명 (+1.3%) |
| Natural increase | −11만 명 (−110,000 people) |
The total fertility rate rose to 0.80 births per woman, from 0.75 in 2024. The number of births has increased for a second consecutive year.
Yet natural decrease remains at −11만 people. Even with more babies being born, the population is shrinking. These two figures moving in opposite directions can be confusing, but births would need to rise several times above their current level to catch up with deaths.
The regional structure is similar. Among 17 cities and provinces, Sejong was the only place with natural increase, while the other 16 all recorded declines. The total fertility rate was relatively high in South Jeolla at 1.10 and Sejong at 1.06, while Seoul was lowest at 0.63.
Japan’s “only Tokyo grew” and South Korea’s “only Sejong grew” may appear to point in opposite directions, but the structure is the same. People concentrate in one place, while the rest empties out.
Three takeaways from this release
A rebound in the fertility rate and an end to population decline are not the same thing. South Korea’s births increased for 2 years, yet its population still fell by 11만 people. Reading these as the same story leads to mistaken judgments.
Total-population figures can make the decline appear gradual. In Japan, foreign residents numbering 35만 covered part of the decrease. It is necessary to make a habit of checking which statistic is being cited.
National averages conceal regional differences. Even if 46 places decline and 1 grows, the national figure is still presented as a single number. You need to look separately at the figures for where you live.
The population of your city, county, or district can be checked immediately by age group through the Ministry of the Interior and Safety’s Resident Registration Population Statistics. Birth and death statistics are posted by city and province on the Korean Statistical Information Service (KOSIS). Both are available without logging in.
Not 1억2000만, but 67만 and 159만
What Japan experienced after 42 years is not identical to what South Korea will experience. Their population structures and immigration policies differ.
Still, the statistical table of a country that got there first indicates which lines we should watch in the future. In this release, those were not 1억2000만, but 67만 and 159만.
Sources
- Aju Business Daily Japan’s Japanese-national population falls below 1억 2000만 for the first time in 42 years… Foreign population reaches 400만 for the first time
- News1 Japan’s Japanese-national population falls below 1억2000만 for the first time in 42 years… Foreign population rises
- Republic of Korea Policy Briefing 2025 Birth and Death Statistics (Preliminary)
Japan’s figures are based on the Basic Resident Register as of January 1, 2026, while South Korea’s figures are preliminary Statistics Korea data. Because the compilation standards differ, they should be read as a structural comparison rather than a direct comparison.