Japan's population has been decreasing for 16 years in a row, and in 2024 they made a new record. According to France24, and also reported by Finnish YLE, in 2024 the amount of Japanese nationals decreased by more than 900,000 people.
To be more accurate, in 2024 the number of Japanese fell by 908,574 people, which means 0.75% to a total population of 120.65 million. The prime minister Shigeru Ishiba has called this a "quiet emergency".
On the other hand, the amount of foreign residents is at its highest ever. "There were 3.67 million foreigners as of January 1, 2025, representing nearly three percent of the whole population in Japan ---".
So as a whole, Japan has the world's second-oldest population after Monaco (according to the World Bank).