Japan's population fell by three million in the past five years. This is the largest drop since records began in 1920. The government released figures for its latest five-yearly census. It shows that the number of people in Japan in October was around 123 million. This is a fall of 2.5 per cent. The census is the third in a row to show a decrease. Japan's government said that the population decline is advancing. It said it would take actions to address it.

A big reason for the decline is very low birth rates. In 2025, there were just over 700,000 births, compared to 2.5 million in the postwar baby boom. Many governments have taken actions to encourage couples to have babies. These include more child allowances and parental leave, and subsidized early years education. Japan is one of the world's oldest societies. Its greying population is putting a lot of stress on healthcare and pensions.