Short answers, pulled from the story.
Japan effectively annexed Korea on the 22nd of August 1910 with the signing of the Japan, Korea Treaty of 1910. The treaty became effective the same day it was signed by Ye Wanyong and Terauchi Masatake.
As of April 2020, there are 81,889 Korean cultural artifacts located in Japan. This figure includes items relocated from sites such as the Liaodong Peninsula to Pyongyang during the colonial period.
Japanese landownership increased from 36.8 percent in 1916 to 52.7 percent in 1932 through a new system that denied ownership to those unable to provide written documentation. By 1939, about 94 percent of total capital recorded by factories was owned by Japanese entities.
The proclamation Matter Concerning the Changing of Korean Names barred ethnic Koreans from taking Japanese names in 1911 but reversed this position by 1939. Imperial Decree 19 and 20 on Korean Civil Affairs went into effect in 1939 forcing the surrender of traditional clan-based family name systems.
Estimates of deaths range between 270,000 and 810,000 among conscripted laborers in Korea and Manchuria with 60,000 of the 670,000 mobilized laborers dying in mainland Japan alone. During the Battle of Tarawa only 129 of the 1,200 laborers survived out of a group found as far as the Tarawa Atoll.