The University of Cambridge has access to 1.75 million + ebooks from a wide variety of publishers and platforms. For the full list, please consult the Ebooks page.
This page is for Japanese-language ebooks only.
KinoDen is a Japanese academic ebook service for libraries from Kinokuniya.
Use 検索 to search for books. Some of the titles in KinoDen have been purchased by Cambridgue University Library.
(contact japanese@lib.cam.ac.uk to request new titles)
JKBooks is the electronic book platform for JapanKnowledge.
JKBooks offers a collection of publications containing specialised content including Gunsho Ruiju, Shiryo Sanshu etc. It features fast searches for desired content, and unaltered PDF page images of original books, while retaining the inherent ease of reading physical books in its display.

Maruzen Ebook Library is Japanese multidisciplinary ebook platform for academic scholarly publications.
Provide a search function and access to the ebooks mostly in Japanese. The number of pages that can be printed or downloaded per title is displayed on the screen for earch title.
(Contact japanese@lib.cam.ac.uk to request new titles.)

Aozora bunko
Comic Walker (manga in Japanese, includes some free material)
Google Books