Mandato del Pacífico Sur
As for prefectural population before 1945, prefectures that constituted are only given. or Southern Sakhalin was officially incorporated into Japan Proper since March 26, 1943 until the end of the World War II, while Taiwan, Kwantung Leased Territory, Korea and South Pacific Mandate were treated as . At the end of war, Japan lost possessions of Southern Sakhalin (Karafuto-fu), Kuril Islands (part of Hokkaidō), Ogasawara Islands (part of Tōkyō-to), Amami and Tokara Islands (part of Kagoshima-ken), Daitō Islands and Ryukyu Islands (Okinawa-ken). For the population of the colonies of the former Empire of Japan, see Demographics of Imperial Japan.