Short answers, pulled from the story.
Nanshin-ron became official policy after 1935 when it was formally adopted by state leadership. The doctrine emphasized expansion into Southeast Asia to secure resources and space for Japan's growing population.
Japanese emigrants began moving to Southeast Asia shortly after the Meiji Restoration in 1868. They established communities in British Malaya, Singapore, the Philippines, and French Indochina during this period.
The Caroline Islands, Mariana Islands, Marshall Islands, and Palau fell under Japanese control following the conflict. In 1919, these island groups officially became a League of Nations mandate administered by the Imperial Japanese Navy.
Japan began constructing fortifications in Palau, Tinian, and Saipan during the 1920s despite restrictions from the Washington Naval Treaty. Authorities camouflaged these sites as fishing net drying areas or farms producing rice, sugar-cane, and coconuts.
Karayuki-san were women who worked in brothels across Southeast Asia among the first wave of human expansion into southern territories. These individuals represented the initial phase of settlement before formal political doctrines took shape.