順天堂大学
was a Japanese linguist who started his career lecturing at Juntendo University, and went on to become full professor at Kyoto Sangyo University. One of the world’s foremost authorities on the Altaic languages, he later made important contributions to the mixed-language theory of the origins of Japanese. Denis Sinor regarded him, together with Shirō Hattori, Samuel E. Martin, and Osada Natsuki as one of the four scholars who have done most to throw light on the origins of the Japanese language.