# R4 | anthropic/claude-opus-5 | run 2

## Prompt

As of the most recent available estimate, what is the population of Japan, and is it increasing or decreasing? Give the figure and year, and cite sources.

## Response

Japan's population is declining, and has been for well over a decade. The most recent official figure from Japan's Statistics Bureau puts the total population at roughly **122.93 million as of July 1, 2026** (provisional estimate), down about 440,000 people — or 0.35% — from a year earlier (Statistics Bureau monthly estimate published July 21, 2026).

## Latest Official Figures

| Reference date | Total population | Year-on-year change |
|---|---|---|
| July 1, 2026 (provisional) | 122.93 million | −440,000 (−0.35%) |
| Feb 1, 2026 (final) | 122.975 million | — |
| Oct 1, 2025 (final) | 123.219 million | −583,000 (−0.47%) |

Sources: Japan's Statistics Bureau reported 122.93 million for July 1, 2026, and a finalized 122,975,000 for February 1, 2026 — [人口推計](https://www.stat.go.jp/data/jinsui/new.html). The October 1, 2025 finalized figure was 123,219,000, a drop of 583,000 (−0.47%) from the prior year — [Monthly Report](https://www.stat.go.jp/data/jinsui/pdf/202603.pdf).

## Direction of the Trend

The decline is unambiguous and driven by natural decrease — deaths far exceeding births. As of November 1, 2025, the Japanese-national population was 119.316 million, down 912,000 (−0.76%) year-on-year, while the foreign-resident population rose to 3.887 million, up 331,000 (+9.29%) — [人と仕事研究所](https://apj.aidem.co.jp/current/detail/6087.html). In other words, record immigration is partially offsetting, but not reversing, the shrinkage of the native population.

For longer-term context, Japan's population peaked around 2010 at roughly 128 million and has declined since, and UN projections point to about 105 million by 2050 — [Georank](https://georank.org/population/japan).

## A Note on Conflicting Numbers

Third-party trackers cite somewhat different figures — for example, Worldometer estimates 122,427,731 at mid-2026 — [Worldometer](https://www.worldometers.info/world-population/japan-population/). These derive from UN World Population Prospects modeling rather than Japan's own administrative data, so the Statistics Bureau figure is the authoritative one. Current estimates remain based on the 2020 Population Census, and they will be revised once the basic tabulation of the 2025 Census is published.

Would you like a breakdown of Japan's population by age group, or the regional/prefectural picture?
