In 2023, Japan's population in urban agglomerations of more than 1 million people stood at approximately 65.26% of the population. Forecast data indicates a gradual increase, reaching 65.93% by 2028. Year-on-year growth is relatively modest, with increments ranging from 0.15% to 0.13% over the forecast period. The compounded annual growth rate (CAGR) over five years is approximately 0.20%.

Future trends to watch include:

Monitoring the impact of Japan's aging population on urbanization rates.
Shifts in economic opportunities that could influence migration patterns.
Policy changes promoting regional development that might affect urban agglomeration growth.