pioneers for difficult life supplies and for defense purposes (Kurishima Cruise Diary). In 1945, the Soviet Union invaded Japan and occupied Sakhalin and the Kuril Islands. The Ainu who lived there were repatriated to their home country, Japan, except for those who indicated their willingness to remain. Population The population of the Ainu during the Edo period was a maximum of 26,800, but it has declined due to the epidemic of infectious diseases since it was regarded as a Tenryō territory. According to the 1897 Russian census, 1,446 Ainu native speakers lived in Russian territory. Currently, there are no Ainu items in the Japanese national census, and no fact-finding has been conducted at national institutions. Therefore, the exact number of Ainu people is unknown. However, multiple surveys were conducted that provide an indication of the total population. According to a 2006 Hokkaido Agency survey, there were 23,782 Ainu people in Hokkaido. When viewed by the branch office (currently the Promotion Bureau), there are many in the Iburi / Hidaka branch office. In addition, the definition of "Ainu" by the Hokkaido Agency in this survey is "a person who seems to have inherited the blood of Ainu" or "the same livelihood as those with marriage or adoption." Additionally, if it is denied that the other person is an Ainu then it is not subject to investigation. According to a 1971 survey, there were 77,000 survey results. There is also a survey that the total number of Ainu living in Japan is 200,000. However, there's no other survey that supports this estimate. Many Ainu live outside Hokkaido. A 1988 survey estimated that the population of Ainu living in Tokyo was 2,700. According to a 1989 survey report on Utari living in Tokyo, it is estimated that the area around Tokyo alone exceeds 10% of Ainu living in Hokkaido, and there are more than 10,000 Ainu living in the Tokyo metropolitan area. In addition to Japan and Russia, it was reported in 1992 that there was a descendant of Kuril Ainu in Poland, but there are also indications that it is a descendant of the Aleut. On the other hand, the descendant of the children born in Poland by the Polish anthropologist Bronisław Piłsudski, who was the leading Ainu researcher and left a vast amount of research material such as photographs and wax tubes, was born in Japan. According to a 2017 survey,