Isao SHIMOJIMA (another name as a poet was Kukoku), who was a doctor from Inadani and knew Seigetsu during his boyhood, came up with the idea of collecting Seigetsu's work and asked his real brother Goro SHIMOJIMA, who lived in Inadani, to research it.
伊那谷出身の医師であり、自らも年少時に井月を見知っていた下島勲（俳号：空谷）は、井月作品の収集を思い立ち、伊那谷に居住していた実弟の下島五老に調査を依頼。