In the early 19th century, Ryozo Munakata, a shoya (village headman) in Haji village, Ono gun, who was purporting to be a family of Guji (chief of those who serves shrine, controls festivals and general affairs) asked Naganori TAMADA of Singakukan, Yoshida, Kyoto who visited the Oka clan, to evaluate the ancient documents written in special Kana handed down as "Kami no fumi (Letter of God)" and it was decided that the documents were a gisho (apocryphal book).
19世紀初頭、宗像大社の宮司の一族を称する大野郡土師村の庄屋宗像良蔵が、「神のふみ」として伝わる特殊仮名で書かれた古文書の鑑定を、岡藩を訪れていた京都吉田神学館の玉田永教に依頼したが、偽書と断じられた。