[8] In reference to the people of that region, the same two kanji used to write the word Ezo can also be read Emishi.
[9] Japanese sources that include an etymology describe Ezo as probably originally a borrowing from the Ainu word enciw meaning 'person; people'.
[3][5][6][4] The term is first attested in Japanese in a text from 1153 in reference to any of the non-Japanese people living in the northeast of Honshū, and then later in 1485 in reference to the northern islands where these people lived, primarily Hokkaido, Karafuto (that is, Sakhalin), and the Kuril Islands.
The use of the character for 'shrimp, lobster' might be in reference to the long "whiskers" (antennae) of these animals, alluding to the prominent beards worn by Ainu men.
His small library of Japanese books included Sangoku Tsūran Zusetsu (三国通覧図説, An Illustrated Description of Three Countries) by Hayashi Shihei.