In the mid-Heian period, besides a full name used at the Imperial Court, the use of a pseudonym containing a domain name (myo) followed by a nickname (azana) became popular especially among early samurai warriors who were originally from the eastern provinces.
平安中期ごろ、特に東国の発祥当初の武士層の間で、朝廷との関係において名乗る姓名とは別に、自らの所領（名：みょう）に通称名（字：あざな）を並べる通称が広まっていった。