This paper examines the copyright challenges surrounding the use of map data for disaster prevention and explores how hyper-layering technology offers a viable solution. Based on discussions at the 2024 Digital Archive Society (DA) Session, we analyze how hyper-layering—linking to external data without duplication—avoids infringing upon reproduction or transmission rights under Japanese copyright law. Attorney Kensaku Fukui affirmed its legality, while Professor Kimiro Meguro and others emphasized its practical significance. This paper not only examines this legal arrangement but also looks at the future use of map data for disaster prevention from the viewpoint of disaster prevention and public interest through ethical considerations.

This paper examines key issues in the digital archiving of materials related to the creative production process of film director Nobuhiko Obayashi. Since visiting a storage warehouse in Hiroshima Prefecture in 2023, the author has continuously sought to understand the composition and storage conditions of unorganized audiovisual and textual materials. As a preliminary case study for a larger-scale future investigation of privately held materials, this paper analyzes the research process that underpins such work and clarifies the challenges involved in the “preservation,” “restoration,” “access,” and “utilization” of these materials. It further conceptualizes the practice of provisionally classifying and cross-referencing materials on the basis of specific research objectives as “Research-Led Exploratory Excavation” and aims to explore a sustainable framework for their preservation and use.