 In the census of December 1939, the total population of the South Seas Mandate was 129,104, of which 77,257 were Japanese.By December 1941, Saipan had a population of more than 30,000 people, including 25,000 Japanese.There were over 400,000 people living on Karafuto (southern Sakhalin) when the Soviet offensive began in early August 1945.