“Katsura is shibui”—this persistent slogan originated in two special issues of House Beautiful published in 1960. Themed “Discover shibui” and “How to be shibui with American things,” these publications linked the image of the Katsura Detached Palace with shibui and employed this “untranslatable” word to evoke the notion of richness in simplicity. But as this article shows, Katsura’s global fame can be traced at least back to the early 1920s, when German scholars investigated the imperial villa as an example of Japanese timber construction, followed soon after by Japanese architects and critics. Shibui, in contrast, first became an aesthetic term when the Japanese government promoted it in the 1930s as part of a campaign to encourage foreign tourism. This study reconstructs the process through which a growing number of publications and international exchanges addressed these topics, culminating in the postwar period, when the initial contact between the two genealogies of Katsura and shibui sparked a heated aesthetic debate.