Dai Nihon Teikoku Kenpō | The Constitution of the Empire of Japan (Meiji Constitution)

Kokuritsu Kokkai Toshokan, "Shiryō ni miru Nihon no kindai: Kaikoku kara kōwa made 100-nen no kiseki"

National Diet Library, Online Exhibition: [Modern Japan in Archives]

国立国会図書館 「資料に見る日本の近代 - 開国から講和まで100年の軌跡」  

This website is part of the National Diet Library's online exhibition project and presents images of historically important documents and materials since the Meiji Restoration. The website is divided into five sections, corresponding to different periods of Japanese history from 1868 - 1945. In each section, the users are able to view materials pertaining to the constitution, such as the "Proposal for Drafting a [Meiji] Constitution (Rikkokukengi)" – written by Miyajima Seiichiro, who was the Sain legislator in 1872. The collections are small in quantity but of high quality. The website is easy to navigate and is also available in English.
 

Kokuritsu Kōbunshokan, Ajia Rekishi Shiyō Centā, Topikkusu: "Dai Nihon Teikoku Kenpō"

National Archives of Japan,  Japan Center Asian Historical Records, Topics: "The Constitution of the Empire of Japan" 

国立公文書館 アジア歴史資料センター トピックス:「大日本帝国憲法」 

This website provides primary materials from Japan’s Asian Historical Records (National Archives of Japan) related to the Constitution of the Empire of Japan. The catalog includes the original copy of the Meiji Constitution.