The eight Buddhist monks who went to Tang called "nitto hasso" (also called "nitto hakke"), namely Saicho, Kukai, Eun, Engyo, Jogyo, Soei, Ennin and Enchin, made a catalogue of imported items (shorai mokuroku) in which they recorded the list of books which they brought back from Tang.
まず、唐に留学していた「入唐八僧」（「入唐八家」とも、最澄、空海、恵運、円行、常暁、宗叡、円仁、円珍）と呼ばれる僧侶達が帰国した際に持ち帰った書物などを記録した将来目録（請来目録）が作成された。