Kansatsushi (inspector) (観察使)
Kansatsushi refers to a government post which was established in Tang Dynasty China, in Yi Dynasty Korea, and in Japan in the early Heian period, for the purpose of inspecting the local administration. This was Ryoge no kan (class outside of the Ritsuryo system) which was not regulated in the Ritsuryo codes for both Tang and Japan. During the Yi Dynasty, it was an institution under the direct control of the King.
Tang
In the period of Genso (Tang), Do (administrative district) of which the number had been 10 was increased to 15, and saihoshochishi (auditor) were placed in each Do. Saihoshochishi was later changed to kansatsushochishi (abbreviated as kansatsushi) by changing its name. Kansatsushi was a nominal post for inspection, but, effectively held authority on the inside of Do. Many kansatsushi who concurrently assumed the post of Setsudoshi (military governor) established around the same time also controlled the administration and military, and held a lot of power.
For details, refer to the article of 'Hanchin.'
Japan
In Japan, in around 797 in the initial Heian period, Emperor Kanmu aiming at the thorough performance of local administration established Kageyushi (Board of Discharge Examiners) which audited the administrative performance by chihokan (a local official) (kokushi (provincial governor)). Kageyushi strictly audited the administration by kokushi, and attained some progress in improving the local administration.
However, when Emperor Kanmu died in 806, Emperor Heizei, the successor, advocated innovating politics, and in June of the same year, he abolished Kageyushi as part of this innovation, and newly established kansatsushi. At first, kansatsushi was established in each of Rokudo (six districts) (Tokaido, Hokurikudo, Sanindo, Sanyodo, Nankaido and Saikaido) excluding Tosando, and was also called Rokudokansatsushi. It was decided that the post of kansatsushi should be concurrently assumed by sangi (councillor), one of the members of Giseikan (Legislature). Kansatsushi was an important post on par with sangi.
In the next year, 807, kansatsushi was also established in Tosando and Kinai region (the five capital provinces surrounding the ancient capitals of Nara and Kyoto). In addition, sangi was abolished, and only kansatsushi remained. It seemed that kansatsushi enthusiastically inspected the local administration, and "Nihonkoki" (Later Chronicle of Japan) had recorded that each kansatsushi took various measures to reduce people's burdens.
Under circumstances where a relation between Emperor Heizei who abdicated from the throne in the previous year, 809, and Emperor Saga was aggravated in 810, Emperor Saga issued the imperial edict to abolish kansatsushi and bringing back sangi in July of the same year. As a result of this, the four-year history of kansatsushi ended.