What is the size of Japan by area?
Exclusive economic zone of Japan
Japan has the eighth largest Exclusive Economic Zone (EEZ) in the world. The total area of Japan is about 377,973.89 km². Japan's EEZ area is vast and the territorial waters (including: the Seto Inland Sea) and EEZ together is about 4.48 million km².
Kagawa Prefecture
Kagawa is currently the smallest prefecture, by area, in Japan. Osaka Prefecture held that title until Kansai International Airport was reclaimed from the ocean in the early 1990s, pushing its land area slightly above Kagawa's. Kagawa is a relatively narrow prefecture located between the mountains of Shikoku and the sea.