Historian. After graduating from Tokyo Senmon Gakko (now Waseda University) in 1891, he studied under SHIRATORI Kurakichi. He worked as a junior high school teacher, then as a researcher in the Mansen (Manchuria and Korea) Historical and Geographical Research Department of the South Manchuria Railways Company, and later became a professor at Waseda University. In 1940, he was indicted for his writings violating the dignity of the imperial family, which was prohibited by the Publication Law, and he resigned. He empirically researched the history of thought of the Japanese people and also published works on the study of Chinese thought. He was awarded the Order of Culture in 1949. His representative works include Kojiki oyobi Nihon syoki no Kenkyu (New study on Kojiki and Nihon syoki) (1924) and Shina Siso to Nihon (Chinese Thought and Japan) (1938).