The ATEVI are a fictional race, presented in C.J. Cherryh's Foreigner series.
The native beckoned to him, once, twice, unmistakably, to get up. Impossible not to recognize the intelligence, the purpose, the civilized nature of the native, who was black as night, with a face not by any remotest kinship human, but sternly handsome in its planes and angles.
A third time it beckoned. He saw no imminent threat as he rose. It was imposingly tall -- more than a head taller -- and broad-shouldered.
Atevi are tall humanoid aliens posessed of black skin, and golden eyes. Their features are depicted on the cover of Foreigner as being somewhat elongated, their ears pointed, with somewhat descending lobes. Both the males and females of the species wear their hair long, and braided down the back, sometimes with ribbons or other ornamentation to denote rank and/or association.
"...atevi didn't walk through people's doors uninvited, not in a society where everyone was armed and assassination was legal."
To atevi, "like" is a word you use to describe food - There is only Man'chi, or duty by association. You do as you are led to do by your association, and follow your duty in all things. You do not have friends, only duty - But there is a certain amount of trust you can share with whose who share your Man'chi. One's Man'chi can change, however. "Fourteen words, the language had for betrayal, and one of them doubled for 'taking the obvious course'."
Assassination is an acceptable form of settling disputes, but must be done properly. One is required to file a notice of intent; Failure to do so is a breach of law. Assassins in turn must be licensed with their Guild, though one may fill one's contract oneself.
The Atevi believe in finesse in all things, which consists of "proper action." Destroying a thing to acheive a goal which could be had by other means is contrary to proper action or behavior, especially in the case of the Assassins Guild.
Atevi have a head for math, possibly biological in nature. Everything is mathematics, causing them to resist such things as identification numbers. Numbers are either felicitous or not, and can often be interpreted one way or another. This is expressed in the language as well as the culture. The dimensions of a piece of furniture, for example, give it its own numeric properties, and these govern the appropriate placement of furniture in the room, which in turn has its own numbers to be considered.
Atevi are governed by a relatively simple system of rank, which is however complicated by Man'chi. The topmost rank is the Aiji, meaning roughly "firstmost" or "headmost" - The glossary of Foreigner defines Aiji as lord of central association. One's name, description, or office comes first; Tabini-Aiji being Aiji of the Western Association. A qualifying word to set one Aiji apart from another comes after, thus his mother is known as the Aiji-dowager. Only an Aiji has questionable Man'chi, or Man'chi only to their own ideals. Nadi is a polite honorific used interchangably for both genders. It can be used preceding a name as we would use mister (Nadi Bren) or after a name as -san is used in the Japanese language (Bren-Nadi.) The additional suffix -ji implies honor given, as in aiji-ji or nadi-ji.
Propriety is a significant factor in Atevi culture. It is important, especially for those in power, to maintain a kabiu appearance - 'in the spirit of good traditional example' (Foreigner.) What specifically constitutes kabiu behavior may vary from province to province; In the Aiji's society, it includes eating game in season, and observing the importance of numbers meticulously.
Foreigner. C.J. Cherryh. DAW, November 1994.