data japan 2023WELCOME MESSAGE. Hi, everyone, We are pleased to announce that the 3rd B Data Machine Learning in Healthcare in Japan (Datathon-Japan 2025) will be held at Tokyo MedicalThe 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