Across Japan, the number of resident foreigners reached 3,956,619 by June 2025, a new record, up about 1 million from 2022. Using the Immigration Services Agency's foreign residents statistics and the national resident population data, the article ranks 1,892 municipalities into three size bands and lists the top five in each. In the under-10,000 category, Akaigawa-mura in Hokkaido leads with foreign residents rising from 28 to 381 in three years (1,260.7%). The surge is attributed to the Kiroro Resort’s internationalization, including the December 2023 reopening of Club Med Kiroro Grand. Nearby Kyowa Town and Kimobetsu also show strong gains, while Shintoku and Kariwa are among the other top gainers, reflecting spillover from the Niseko area tourism and related housing demand.