Context and Historical Transitions in 20th-Century Japanese Literature on “Saiiki” and “The Silk Road” ：A Quantitative Text Analysis of Holdings in the National Diet Library of Japan

In Japan, books and cultural content related to the “Saiiki” and the “Silk Road” have experienced recurring popularity throughout the 20th century. Past research has primarily focused on major authors and works, forming a skeletal historical narrative, while a broader corpus remains largely unexplored in library archives and databases. This study organizes these extensive materials to clarify the scope of discourse on “Saiiki/Silk Road.” Using text mining tools, such as NDL Ngram Viewer, and KH Coder, I analyzed the frequency and historical transitions of these terms in Japanese texts. Quantitative analysis of titles from the National Diet Library’s databases further revealed their interconnected yet contextually distinct historical trends.