On hakase (Professor of Pronunciation of Chinese Language) (音博士)
On hakase (also known as Koe no hakase) was a hakase position (professor) established under the Ritsuryo system in Japan. The On hakase belonged to Daigaku-ryo (Bureau of Education under the Ritsuryo system), and taught hakudoku (pronunciation of Chinese language in kanon (Han reading of Chinese characters)) of Keisho (most important documents in Confucianism) to gakusho (students) of Myogyo-do (the study of Confucian classics). There were two fixed hakase, and the rank was equivalent to Jushichiinojo (Junior Seventh Rank, Upper Grade).
"Nihonshoki" (Chronicles of Japan) has a description that On hakase (SHOKU Shugen and SATSU Kokaku) existed in 691, and it is known that toraijin (people from overseas, especially from China and Korea, who settled in early Japan and introduced Continental culture to the Japanese) mainly assumed this post. It was natural that the toraijin seldom used Chinese language while staying in Japan, and very few people learned only Ondo (the study of pronunciation of Chinese language).
However, in the early Heian period when the influence of Tang culture became stronger, kyakushiki (amendments and enforcement of regulations of the ritsuryo) to establish 'onsho' was issued on May 10, 817 due to interest in kanon. In addition, an examination of kanon held by the On hakase was imposed on government officials (esp. one of low to medium rank) and Buddhist monks to be dispatched as members of a Japanese envoy to Tang Dynasty China. But, this was temporary, and in the mid Heian period, the On hakase became an honorary post assigned to scholars from the Nakahara clan and the Kiyohara clan which monopolized Myogyo-do.