data japan 202319-1 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8668 Japan ©1996 Statistics Bureau, Ministry of Internal Affairs and Communications (JCN2000012020001)The 2025 population density in Japan is 338 people per Km2 (875 people per mi2), calculated on a total land area of 364,555 Km2 (140,755 sq. miles). Largest Cities in Japan # City Name