If I am including a publication listed by a title written in nonroman characters in my works-cited list, should I provide in my parenthetical citations the title in the original script or the transliterated title?
Use whichever method will be most useful to your reader. If you are citing a report, for example, and there is only one report listed by title, it would be fine to list the work in the original script in your parenthetical citations, since your readers—whether or not they are familiar with the language—will be able to find the entry in the works-cited list:
A recent report noted that private elementary schools in Japan are proliferating (平成26年度調査 3).
平成26年度調査結果の概要(初等中等教育機関) [Heisei 26 nendo chōsa kekka no gaiyō (shotō chūtō kyōiku kikan); Summary of 2014 Fiscal Year Survey Results (Primary and Secondary Educational Institutions)]. Japan Ministry of Education, Culture, Sports, Science, and Technology, 19 Dec. 2014, www.mext.go.jp/component/b_menu/other/__icsFiles/afieldfile/2014/12/19/1354124_2_1.pdf.
If there is more than one report listed by title, and your audience is primarily composed of people who know the language (e.g., students in a Japanese language class, readers of a Japanese studies journal), you might still list the titles in the original script. But if your audience includes readers not familiar with the language, you might list the transliterated titles in your parenthetical citations so that all your readers can more easily distinguish the titles:
A recent report noted that private elementary schools in Japan are proliferating (Heisei 26 nendo chōsa 3).
Published 18 July 2019