Many old manuscripts such as 'Oshimabon (Oshima book),' which is a manuscript in the 'Aobyoshibon' line, and the 'Kawachibon' line manuscripts (which had already been considered lost in those days) were found, and these manuscripts were compared from the academic perspective.
多くの学者の努力によって「大島本」などの「青表紙」系統の写本や当時はすでに失われてしまったと考えられていた「河内本」系統の写本など多くの古写本が発見され、学問的な比較作業が行われた。