Azuma Hyakkan (東百官)

Azuma Hyakkan referred to a person's name that looked like a government post and was used by the samurai in the Kanto region. However, Azuma Hyakka was not a formal government position of the Imperial Court, but was just a name created by imitating a government post of the Imperial Court. Like Hyakkan na (a name taken after his/her or family's official rank), Azuma Hyakkan was put after Miyoji (a family name) and before Imina (a personal name).

Summary
Azuma Hyakkan is also called Souma Hyakkan, and there is a legend that these names were introduced as a government post system by TAIRA no Masakado when he named himself a new emperor and formed a new government.

In contrast to Hyakkan na based on the organization of government according to the ritsuryo codes of the Imperial Court, this government-post-like name used in Kanto was called Azuma Hyakkan or Buke Hyakkan. Originally, a samurai's appointment to an officer was applied to the Imperial Court through the bakufu (Japanese feudal government headed by a shogun); Baishin (indirect vassal) and Roju (vassal) were not given any government position. After the Onin War, however, there were some cases that Daimyo (Japanese feudal lords) gave Hyakkan na to their vassals without permission, and in other cases, they even created Nanori (a name one refers to himself) similar to actual Shitokan (four classifications of bureaucrats' ranks). These government-post-like Nanori which were created without any historical background and used in the samurai society were called Azuma Hyakkan, and were distinguished from the actual names of government positions.
Azuma Hyakkan was also used in the Edo period, and scholars in the Edo period criticized it by saying, 'You should not announce yourself as such without an ancient and honorable origin.'
However, even influential samurai families as well as children of good families took the name of Azuma Hyakkan.