Geppō 月報, journal‐like pamphlets issued within monographic sets, are important resources containing material that complements the volumes with which they are issued. Typical contents for geppō include: brief academic articles, chronologies, bibliographies, reminiscences‐as‐biographies, editorial notes, biographical sketches of contributors to the series, errata and corrigenda, tables of contents, indexes, and information about other volumes in the series. Despite their wealth of contents—much of which can be found only in these publications—geppō traditionally have been overlooked and underappreciated. In many libraries, they have been lost or discarded. Based on an assessment of the current situation of geppō at the University of Pennsylvania Libraries, as well as on a review of topical Japanese literature, I propose a collaborative database to provide access to these valuable but neglected resources. In this article, I will introduce the history of geppō, including their evolution over time and their treatment in libraries. I will then discuss challenges concerning collection of and access to geppō using a case study of one title held at the University. Finally, I will offer recommendations for consistent preservation methodologies of geppō and for the transformation of their analog content into indexed data.