It is possible to assume the process of writing by the descriptions of both Mumyozoshi (critique of tales), which was completed at the beginning of the 13th century, and Fuyo Wakashu (collection of Japanese poems based on fictional stories), which was compiled at the end of the same century.
この経緯については、13世紀初頭に成立した無名草子や同世紀後半に成立した風葉和歌集の記述から推測可能である。