Arai Hakuseki
In the 18th century, Arai Hakuseki suggested that the ancient stone tools in Japan were left behind by the Shukushin. Later, Philipp Franz von Siebold argued that the Ainu people were indigenous to northern Japan. Iha Fuyū suggested that Japanese and Ryukyuan people have the same ethnic origin, based on his 1906 research on the Ryukyuan languages. In the Taishō period, Torii Ryūzō claimed that Yamato people used Yayoi pottery and Ainu used Jōmon pottery.