Emishi

Japanese: えみし

...The Ainu (Shisamu means neighbors in Ainu) were called Ezo or Ezojin until the end of the early modern period, influenced by the Chinese idea of Sinocentrism. However, the ancient Emishi mainly referred to the inhabitants of the Oshu region and north, and did not refer to the Ainu themselves. Also, since the Gilyak and other ethnic groups living in the lower reaches of the Heilongjiang (Amur River) and Sakhalin called the Ainu (Sakhalin Ainu) Kugi and Kui, Chinese documents wrote them as Kukei in the Yuan Dynasty, Kuku and Kui in the Ming Dynasty, and Kuye, Kuye, Kuye, and Kupe in the Qing Dynasty.

From [Ezo]

...In ancient Japanese history, this term was used to refer to the indigenous people of northeastern Japan. However, the name and meaning of the term vary greatly depending on the time and region, making it difficult to define its characteristics in a univocal way. It is also difficult to determine how it relates to the Ainu. This term was originally based on the Chinese concept of people who did not submit to the imperial court, which meant the "center" politically and culturally, and in that sense were uncivilized and barbaric people, so it does not match the racial concept of whether they were Ainu or Japanese.

From Ezo

...refers to the area inhabited by the Emishi, and later the Ainu. As the concept of the Emishi changed, so did the concept of the region of Emishi. In the pre-Taika period, people who stood outside the central government and were in an antagonistic relationship to it were called Emishi, and the characters "Kehito" and "Yi" were mainly used, meaning "wild ones" and "rebellious people," and did not refer to people living in a specific region, but after the Taika Reforms, people who mainly lived in the Hokuetsu and Oshu regions came to be called Emishi, and the characters "Ezo" and "Yi" were used.

From 【Prisoner】

…In ancient Japan, it referred to Emishi (Ezo or Emishi) who were captured or surrendered and placed under state control. They were also called Ezo-shu. …

*Some of the terminology explanations that mention "Emishi" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

Japanese:

…シサムはアイヌ語で隣人の意)は，中国の中華思想の影響を受けて近世末まで蝦夷（えぞ）･蝦夷人と称した。ただし古代の蝦夷（えみし）は，主として奥羽地方以北の住人を指した語で，アイヌそれ自体を指した語ではない。また黒竜江(アムール川)下流域や樺太に居住するギリヤークほかの諸民族がアイヌ(樺太アイヌ)を〈クギ〉〈クイ〉と称したため，中国の文献では，元代には〈骨嵬〉，明代には〈苦兀〉〈苦夷〉，清代には〈庫野〉〈庫葉〉〈庫頁〉と記された。…

【蝦夷】より

…日本古代史上，東北日本に拠った土着の人たちをひろくさしたことば。ただしその呼称･内容は，時代･地域によって大きく異なり，その性格を一義的に規定することを困難にしている。また，アイヌとどうかかわるかもむずかしい問題である。このことばは，もともと政治的･文化的に〈中央〉を意味した朝廷に従わない人たち(まつろわぬ民)，その意味で未開･野蛮な人たち(あらぶる人)をさす中華観念にもとづいているから，人種的観念であるアイヌか日本人かという議論の立てかたとは一致しないところがある。…

【蝦夷地】より

…蝦夷の居住地，のちアイヌの居住地を指す。蝦夷観念の変化に伴い蝦夷地の地域概念にも変化がみられた。大化前代には中央政府の外に立ってこれと敵対関係にある人々をエミシと呼び，おもに〈毛人〉〈夷〉という文字をあて，その意味も〈あらぶる者〉〈まつろわぬ人々〉ということで，特定の地域に住む人々を指すものではなかったが，大化改新以降は，主として北越･奥羽地方に住む人々をエミシと呼ぶようになり，文字も〈蝦夷〉〈夷〉をあてるようになった。…