Nobility

Nobility are the aristocratic class of the world of Ascendance of a Bookworm.

Nobility represent the upper-half of the strictly caste-based society of the story's world. The lower-half is simply commoners. The class division is so large that, for most purposes, Nobility can act with near-total impunity when dealing with commoners.

The primary distinguishing difference between nobility and commoners is that, with all but the rarest exceptions, nobility possess mana, while commoners do not. (In truth, all living things possess mana, but it is typically of such a small amount that it cannot be manifested; the defining difference, then, is that commoners would have a near-imperceptible amount while nobles would have more clearly detectable quantities.) Mana was the original reason for the separation of the classes, and even among nobility the amount of mana you possess can drastically change how you are treated by other nobles.

Having noble birth does not grant one formal recognition as a noble within noble society, though you are still treated as one by commoners, and receive significant deference and respect by your family's level of noble status in general. In order to gain official recognition, one must attend the royal academy, which also is where nobles learn to control and utilize their mana; prior to that (or for those nobles who do not attend), nobles need to use magic tools to drain away the excess mana, or it would affect them with the Devouring, the same way as mana does a commoner (nobles generally do not run that risk, however, as acquiring the magic tools necessary is easy for them).

Tiers of Nobility
Nobility are ranked into three primary levels. The tier is not an indication of any title/rank, because those only come with control of land. The hierarchy between the tiers is nearly as strict as between noble and commoner -- so much so that even a laynoble who shows insufficient deference to a mednoble risks execution for their insubordination.
 * Archnobles (上級貴族 [じょうきゅう きぞく - joukyuu kizoku], literally: "high-class nobility") represent the highest tier among nobility. They typically have the most mana among nobles.
 * Mednobles (中級貴族 [ちゅうきゅう きぞく - chuukyuu kizoku], literally: "mid-class nobility") represent the middle-tier of nobility.
 * Laynobles (下級貴族 [かきゅう きぞく - kakyuu kizoku], literally: "low-class nobility") represent the lower-tier of nobility. They typically have only a little mana.

Titles and Classes of Nobility (landed nobility only)
Recognized nobles with governed land are granted a ranked title according to their status. Only those with land have such ranks, which fall into three classes: Zent, Aub, and Giebe. For Zent and Aub, which only have one title each within the class, they are essentially interchangeable with the title. While the story thematically is reminiscent of North-Central Europe during the early medieval period, the structure of landed nobility in Ascendance of a Bookworm is very clearly modeled after feudal Japan, where an ultimate authority technically exists in the Emperor, but the feudal lords have near-total autonomy within their territory (including the granting of titled nobility positions under them) and even engage in open warfare against other feudal lords.
 * Zent (ツェント) is an archnoble class representing the ruler of a country. The term is introduced in Part 5, Volume 2.
 * King/Sovereign (王 [おう - ou])
 * Aub (アウブ) is an archnoble class representing the person ruling a region in the direct name of the Zent, and to that end granted the full authority of the Zent within that region. The term is introduced in Part 2, Volume 4.
 * Archduke (領主 [りょうしゅ - ryōshu], literally: "Feudal/Territorial Lord")
 * Giebe (ギーベ) is a class representing the person governing a local region of an Aub's territory, and under direct authority of the Aub. Giebe can be archnobles, mednobles, or laynobles. The term is introduced in Part 2, Volume 4.
 * Count (伯爵 [はくしゃく - hakushaku]) a landed archnoble of the Giebe class.
 * Viscount (子爵 [ししゃく - shishaku]) a landed mednoble of the Giebe class.
 * Baron (男爵 [だんしゃく - danshaku]) a landed laynoble of the Giebe class.

Other Noble Titles

 * A member of the Knight's Order is recognized as a knight, and often addressed as such (using the common modifiers "Sir" for men and "Dame" for women). They may be a member of any tier of nobility, though the commander of the Knight's Order will always be a senior archnoble. Although it is rare, they may also possess a landed nobility title.