data japan 2023Natural gas and LNG Data Hub 2025 ... This section covers trends and outlook for Japan’s primary energy supply and demand, power generation capacity and output, and consumption,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