Urban Development in Japan 13 indicators covering urban development for Japan. IndicatorLatest Year10-yr change Rank Population in the largest city 32.5% 2025 up 1.4% 66th Population density 341.55 people per sq. km of land area 2023 down 2.3% 35th PM2.5 air pollution, mean annual exposure 11.45 micrograms per cubic meter 2023 down 11.7% 144th Population in urban agglomerations of more than 1 million 80.94 million 2025 down 0.4% 5th Population in urban agglomerations of more than 1 million, per capita 0.6561 units per person 2025 up 2.6% 5th Population in urban agglomerations of more than 1 million, annual -0.222 % change on previous year 2025 down 208.0% 119th Population in urban agglomerations of more than 1 million, per unit 0 units per US$ of GDP 2025 up 1.8% 82nd Population in urban agglomerations of more than 1 million, per square 222.95 units per square kilometre 2023 up 0.4% 7th Population in largest city 37.04 million 2025 down 0.6% 1st Crude steelmaking capacity 113.6 Tonnes 2025 down 13.2% 3rd Africa's Development Dynamics (AfDD) Table 23 - Ecological 1,808 Hectares 2020 up 21.6% 9th PM2.5 air pollution, population exposed to levels exceeding WHO 76.8% 2017 down 16.6% 168th Transport equipment indicators — Available seat capacity for schedule 421.93 Per 1 000 inhabitants 2016 up 40.2% 31st