Sui generis
In sociology, the "sui generis" is what has been externalized, then internalized in the overall public and becomes a part of society that simply exists in its construct. It is not something that is not thought to have been created, because it is imbedded in everyone's way of thinking and being. Instances include the idea of love, or going to school, or clothing belonging to a specific gender. These examples are "sui generis" for they simply exist in society and are widely accepted without thoughts of where they come from or how they were created.
Japanese name
Historically, "myōji", "uji" and "sei" had different meanings. "Sei" was originally the patrilineal surname which is why up until now it has only been granted by the emperor as a title of male rank. The lower form of the name "sei" being "tei" which is a common name in Japanese men, although there was a male ancestor in ancient Japan from whom the name 'Sei' originally came. There were relatively few "sei", and most of the medieval noble clans trace their lineage either directly to these "sei" or to the courtiers of these "sei". "Uji" was another name used to designate patrilineal descent, but later merged with "myōji" around the same time. "Myōji" was, simply, what a family chooses to call itself, as opposed to the "sei" granted by the emperor. While it was passed on patrilineally in male ancestors including in male ancestors called haku (uncles), one had a certain degree of freedom in changing one's "myōji". See also Kabane.