Mainstream Japanese historiography arose out of a fusion of Western historiography, as introduced by the German Ludwig Riess in 1887, and the Chinese scholarly tradition of evidential research (kaozheng 考證 or kōshōgaku 考證學), which had been established in Japan since the Edo period (1603–1868). Japanese historiography on East Asia (Tōyōshi) was a field led by Shiratori Kurakichi 白鳥庫吉 (1865–1942) which generally followed the negative, orientalist portrayals of China and Korea by the West, while categorizing Japan as separate from both Asia and the West, but as on an equal footing with the West. What Korean historians refer to as Japanese "colonial historiography" can be traced to Tokyo Imperial University's 1890 history of Japan, the Kokushi gan 國史眼, which argued for a common ancestry to Koreans and Japanese (Nissen dōsoron). Based on the Kojiki and Nihon Shoki chronicles, the Kokushi gan asserted that the legendary figures Susanoo, the brother of Emperor Jimmu, and Empress Jingū had ruled or invaded Silla (Korea). Such views of Korea's historical subjugation to Japan became widely accepted in Japanese scholarship, and integral to Japan's national history, as it was presented in other books of Japan's Meiji era (1868–1912), such as Ōtori Keisuke's Chōsen kibun 朝鮮紀聞 (1885), and Hayashi Taisuke's 林泰輔 Chōsenshi 朝鮮史 (1892), made similar arguments. Another theme in Japanese historical scholarship on Korea was Korea's backwardness, which was first argued by the economist Tokuzō Fukuda in 1902, who said that Joseon was equivalent to Japan in the Heian period (794–1185).
