Short answers, pulled from the story.
Korea came under Japanese rule on the 22nd of August 1910, when the Japan-Korea Treaty of 1910 was signed by Prime Minister Ye Wanyong and Japan's Minister of War Terauchi Masatake. Japanese colonial rule lasted 35 years, ending on the 15th of August 1945 with Japan's surrender to the Allied forces.
Japan used a racial theory called Nissen dosoron, which claimed that Koreans and Japanese shared mythological ancestors and that Koreans were therefore inherently Japanese. In a February 1944 speech, Governor-General Koiso cited the ancient Nihon Shoki text to justify the campaign to erase Korean language, culture, and ethnic identity.
The March 1st Movement was a nationwide series of peaceful independence protests that began in 1919 after the sudden death of Emperor Gojong. An estimated 2 million Koreans participated. Japanese authorities suppressed the movement; Korean records document 46,948 arrests, 7,509 deaths, and 15,961 wounded over the following year.
Japan mobilized approximately 5.4 million Koreans to support its war effort beginning in 1939. About 670,000 were taken to mainland Japan, where 60,000 died. Estimates of deaths in Korea and Manchuria range between 270,000 and 810,000.
Many Korean girls and women, mostly aged 12 to 17, were forced into sexual slavery as comfort women for Japanese soldiers, often lured with false promises of factory or other employment. A 1996 United Nations report found that large numbers were forced to submit to prolonged prostitution under frequently traumatic conditions. The Asian Women's Fund estimated the total number of women forced into this system reached anywhere from tens of thousands to hundreds of thousands.
Japan's Land Survey Bureau recognized ownership only on the basis of written documents such as deeds and titles. Farmers with only traditional verbal cultivator-rights lost their land almost overnight. By 1932, Japanese interests controlled 52.7 percent of Korean land, up from 7 to 8 percent in 1910. Most displaced Korean farmers became tenant farmers paying over half their crop in rent to Japanese or Korean landlords.