Myobu is a woman who has Ikai (court rank) above Jugoinoge (junior fifth rank), or a title representing a rank of a government official's wife under the ritsuryo system (a system of centralized government based on the ritsuryo code) in Japan. Or, a synonym (or another name) for Inari-shin (the god of harvest) and its fox.
It is thought that the term myobu was originally derived from male and female officials of myobu as naigenokan (government officials who resided in the capital and government officials who resided in local areas) in China according to "Shurei" (Rites of Zhou) of China. However in Japan, although the name "myobu" was adopted, the content of the job of myobu was completely different from that in china.
(The male official and its naming corresponding to myobu in China was not adopted in Japan.)
Myobu is specified in the article of Nakatsukasasho (Ministry of Central Affairs) in "Shikinryo gige (commentary on the law which stipulates duties of this ministries)." A woman who is higher than goi (fifth rank) in the rank is called uchi no myobu (a senior court lady), and a wife of an official who is higher than goi (fifth rank) in the rank is called ge no myobu. However, myobu was not a government post but was a rank in serving official duties of the government official that she worked for, so that there was no corresponding official court rank, nor a fixed number. In the case of a queen (of imperial family), she was ranked in Ikai even if she was not higher than goi (Fifth Rank) in the rank. Until the Nara period, women working in the palace were called Kyujin (court lady) including myobu, however, myobu was discriminated from kyujin after the Heian period.
Myobu became to serve only in emperor's ceremonies or shinji (a divine service) which were duties of Naishi no tsukasa (female palace attendants); whereas there were prepared kencho no myobu serving for ceremonies such as Choga (retainers' New Year's greeting to the emperor) and Sokui no rei (enthronement ceremony), igi no myobu, mizutori no myobu serving for a ceremony in risshun (the first day of spring), hakase no myobu serving for Kasuga-matsuri Festival, and the like. At the time when the regency was started, myobu became the title for court ladies of churo (the middle grade ladies-in-waiting); they were named after the official position of their father or husband, such as shosho (minor captain) no Myobu, sho (junior assistant minister) no Myobu,nakatsukasa (Ministry of Central Affairs) no Myobu, and kouma no Myobu, which eventually became proper nouns.