一个地方怎样成为日本的一部分？

University of the Ryukyus Library, 琉球古文書その三［琉球処分に関する記録］, Hara Tadayuki Collection, HA016, 1875, catalogue description of the meetings of August 5–7. The account used here is the library's description of a Ryukyuan-side record whose beginning is missing; no dialogue is reconstructed. https://shimuchi.lib.u-ryukyu.ac.jp/collection/hara_tadayuki/ha01601

National Archives of Japan, 日本のあゆみ, “琉球藩を廃し沖縄県を設置する（琉球処分）,” document 公02426, explanatory paragraph. Identifies the 1872 designation of Shō Tai and Ryukyu han, and the April 4, 1879 proclamation. https://www.archives.go.jp/ayumi/kobetsu/m12_1879_01.html

Tagajō inscription, dated 762, Japanese reading reproduced by Tagajō City, “多賀城の歴史,” opening inscription transcription. The distances are reported in the source's units, without a modern conversion or a reconstruction of the complete Emishi boundary. The term on the inscription is not treated as a modern nationality or evidence of a unified neighboring state. https://www.city.tagajo.miyagi.jp/tagajo1300/history/

Tagajō City, “多賀城の歴史,” sections “奈良時代—多賀城創建” and “中世.” Used for the early extent of Mutsu, the establishment's role in expansion, and the archaeological distinction between the ancient compound and later provincial-government references. The page's commemorative etymology of the name is not a basis for attributing intentions to its founders. https://www.city.tagajo.miyagi.jp/tagajo1300/history/

Miyagi Prefecture, Tagajō Site Research Institute, “多賀城跡,” archaeological description of the government precinct, associated working areas and surrounding settlements. Buildings establish functions and occupation, not the consent of every affected community. https://www.pref.miyagi.jp/soshiki/taga/tagajoato.html

David L. Howell, “Making ‘Useful Citizens’ of Ainu Subjects in Early Twentieth-Century Japan,” The Journal of Asian Studies 63, no. 1 (February 2004): 5–29, especially pp. 6–9. Used for earlier subordination and commercial employment, the Meiji agricultural-assimilation interpretation, and the 1909 distinction between actual grants and their maximum. The essay does not extend Howell's later interwar cases backward into the Meiji period. Author-posted article: https://dhowell.scholars.harvard.edu/sites/g/files/omnuum3231/files/dhowell/files/making_useful_citizens_of_ainu_subects_in_early_twentieth-century_japan.pdf

Arano Yasunori (荒野泰典), “『四つの口』と長崎貿易――近世日本の国際関係再考のために――,” Nippon.com, July 19, 2012, sections “『四つの口』の国際関係” and “長崎と3つの大名.” Arano's interpretation distinguishes foreign or differentiated realms from modern national territory and explains the lords' delegated privileges and duties. The broader historical classifications remain attributed to him. https://www.nippon.com/ja/features/c00104/

Naha City Museum of History, “王朝文化と都市の歴史,” Ryukyu Kingdom overview and chronology under “近世琉球,” entries for 1609 and 1611. The account distinguishes Satsuma's domination, Amami's direct administration and the kingdom's continuing relations with China. https://www.rekishi-archive.city.naha.okinawa.jp/history

Naha City Museum of History, “薩摩藩在番奉行所跡,” complete historical description. The 1628 establishment, continuing duties and successive central-government and prefectural uses identify changes in the office's relationship to authority, not an unchanged building or an independently observed working day. https://www.rekishi-archive.city.naha.okinawa.jp/spot/155

Hokkaido Prefectural Archives, “北海道の名前について,” explanation of the 1869 designation and the distinction between dō, provinces and districts. The historical designation does not establish an uninhabited region or the beginning of Japanese intervention. https://www.pref.hokkaido.lg.jp/sm/mnj/d/faq/faq02.html

Hokkaido Prefectural Archives, special exhibition 開拓使文書に拾う北海道史の一場面, “開拓使とは.” Used for the agency's 1869 establishment, combined central and local responsibilities, development program and division of functions in 1882. https://www.pref.hokkaido.lg.jp/sm/mnj/tenji/tokubetsuten/kaitakushitoha.html

北海道旧土人保護法, Law no. 27 of 1899, promulgated March 2, effective April 1; original articles 1–3, read in Nagoya University's 法令データベース transcription. Article 2 distinguishes newly granted land from earlier holdings; the latter are not subject to exactly the same permission rules. The account relies on the statutory text, not the database's AI-generated summary of the proposal. English explanations are paraphrases of the Japanese provisions. https://jahis.law.nagoya-u.ac.jp/lawdb/l/132a0027

Okinawa Prefectural Archives, “1879年3月27日 『沖縄県』の設置,” opening paragraphs and references to the kingdom's documents and the April 4 proclamation. This distinguishes the local announcement and demands on March 27 from the subsequent nationwide proclamation; it is not an independent examination of each document in the referenced archive volume. https://www.archives.pref.okinawa.jp/news/that_day/4631