How many Japanese civilians were there in northeast China during World War II?

After Japan won the Russo-Japanese War, parts of northeast China were forced to open to Japan. Driven by the government, a large number of Japanese nationals, from farmers, craftsmen to middle school students, have come to these areas continuously and become "enclave immigrants". By the middle of 19 10, there will be at least 200,000 Japanese immigrants in all parts of Northeast China. More than 20 years later, the "September 18th Incident" and the establishment of the puppet Manchukuo became the breakthrough for Japanese immigrants to enter China on a large scale. On the eve of the Soviet attack in 1945, there were about 1.6 million Japanese immigrants living in the northeast.