 was a counselor of the second rank in the Imperial court of Japan. The role dates from the 7th century.
The role was eliminated from the Imperial hierarchy in 701, but it was re-established in 705. This advisory position remained a part of the Imperial court from the 8th century until the Meiji period in the 19th century.
This became a Taihō Code office in the early feudal Japanese government or "daijō-kan".
In the ranks of the Imperial bureaucracy, the "Chūnagon" came between the "Dainagon" (major counselors) and the Shōnagon (minor counselors). Imperial honors included the sometimes creation of a temporary or .
The number of "Chūnagon" has varied, from three in 705 to four in 756. There were eight in 1015; and in later years, there were up to ten "Chūnagon" at one time.
Chūnagon in context.
Any exercise of meaningful powers of court officials in the pre-Meiji period reached its nadir during the years of the Tokugawa shogunate, and yet the core structures of ritsuryō government did manage to endure for centuries.
In order to appreciate the office of "Chūnagon", it is necessary to evaluate its role in the traditional Japanese context of a durable yet flexible framework. This was a bureaucratic network and a hierarchy of functionaries. The role of "Chūnagon" was an important element in the "Daijō-kan" (Council of State). The Daijō-kan schema proved to be adaptable in the creation of constitutional government in the modern period.
Highest Daijō-kan officials.
The highest positions in the court hierarchy can be cataloged. A dry list provides a superficial glimpse inside the complexity and inter-connected relationships of the Imperial court structure.
The next highest tier of officials were:
Other high-ranking bureaucrats who function somewhat flexibly within the "Daijō-kan" were; 
The Eight Ministries.
The government ministries were eight semi-independent bureaucracies. A list alone cannot reveal much about the actual functioning of the "Daijō-kan", but the broad hierarchical categories do suggest the way in which governmental functions were parsed:
Left
Right
The specific ministries above are not grouped arbitrarily. The two court officials below had responsibility for them as follows:
Notes.
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