Kogo Shui (古語拾遺)
Kogo Shui is a piece of writing about Shinto during the Heian period. Hironari INBE, a government official, compiled this book in 807. This is a one-volume book.
How this book came into existence
This book is said to have been written on February 13, 807. Some copies say that it was written in 806. However, the postface reads; "Just now, the Emperor's luck turned for the better for the first time…….in the first year of the new era." This reveals that the book was written at least later than May 18, 806, when the era changed from the 25th year of the Enryaku era to the first year of Daido, suggesting that the book being written in the first year of Daido is wrong.
According to the "August 10, 806" section of "Nihon Kouki" (third of the six classical Japanese history texts), a ruling was made by the Emperor on a case filed and fought by the Nakatomi and Inbe clans for over a long period of time. Those who support the view that the book was written in the first year of Daido (806), considered that "Kogo Shui" was evidence of this, based upon when the ruling was made. But, this view goes against the fact that Kogo Shui was written based upon a ruling of August 10.
Nothing is known about Hironari INBE except that he was promoted from Shorokuinojo (Senior Sixth Rank, Upper Grade) to Jugoinoge (Junior Fifth Rank, Lower Grade), as stated in the "November 17, 808" section of the "Nihon Kouki"
Additionally, his promotion is thought to be due to his excellent services at Daijo-sai (the first ceremonial offering of rice by a newly-enthroned Emperor).
According to the postface of this book, however, he was ranked Jugoinoge (Junior Fifth Rank, Lower Grade), but in 807 (when he wrote the book), he should have been ranked Shorokuinojo (Senior Sixth Rank, Upper Grade). The postface must have been altered at a later time.
To complain about the state of his clan and to file a petition
The Inbe was a clan who had traditionally administered religious rituals and services at the imperial court. However, the Nakatomi clan, who had conducted religious services together with the Imbe clan, gained political power and became predominantly engaged in religious services after Taika Reform; a family of the Nakatomi clan, who had been given the name of Fujiwara, had been given the name of Nakatomi, again. This book is thought to have been written to ensure that the Inbe clan was favorably positioned in the imperial court by claiming that it was a legitimate clan for conducting religious services.
To submit a report to the imperial court
The view had been long supported that this book was written for the purpose of complaining about the state the Inbe clan had been in and filing a petition about it. Nowadays, the popular view is that this book was a report submitted by the Inbe clan to the imperial court, that had been conducting investigation to put a legal system in place.
There was a long time dispute between the Inbe and Nakatomi clans over which would take the post of Hoheishi (imperial messenger to a shrine and envoy returning courtesies) at the Grand Shrine of Ise. On August 10, 806, a ruling was made in favor of the Inbe clan. It was after the ruling that this book was submitted to the imperial court on February 13, 807. It would be strange for the Inbe clan to file a petition after they won the suit, making the view that the book was written for the purpose of complaining and filing a petition less convincing.
Emperor Heijo, at that time, had a plan to establish the Shiki (enforcement regulations (of the ritsuryo)). The postface of this book includes a description of "Zo-shiki-no-toshi" ("the year in which regulations were established"), according to which Konin-shiki (regulations of the Konin era) were established in April 820, the eleventh year of Konin, 14 years after the ruling. It would be safe to conclude that this book was a report submitted to the imperial court, that had been conducting investigations to establish enforcement regulations.
It was during this period that "Enryaku gishiki cho" (a list of shrines) was also submitted by the Ise jingu shrine (Grand Shrine at Ise). This is also considered to have been part of a preliminary investigation by the imperial court to establish Shiki and of a series of events that included "Kogo Shui" as well.
Legend of ancient times
Legend of Emperor Jimmu onwards
Eleven sections missing from the legend of ancient times
Legend about Mitoshi gami (enshrined Shinto god, to whom beef was served)
This records the events that occurred during the period from the creation of heaven and earth to the Tempyo era (729-749). This book takes up the legend that had been handed down to subsequent generations among the Inbe clan, but does not involved Records of Ancient Matters (Japan's oldest historical record), Nihon-shoki (the oldest chronicles of Japan), or any other history books.
The Inbe clan is considered to be the descendants of Ame no Futodama, a god who served Amaterasu omikami. That's why this book contains more success stories of Soshin (enshrined ancestors) of the Inbe clan such as Ame no Futotama than the Kojiki and Nihonshoki. For example, when Amaterasu omikami hid herself in Amano iwa to (literally, "the rock cave of heaven"), Ame no Futotama no mikoto played a central role.
This book was cited and used in literature including the Sendai Kuji Hongi, Honcho Gatsuryo, Seiji yoryaku, Chokan-kanmon, Nenju Gyoji Hisho, Syakunihongi, and the books of Ise Shinto. This reveals that this book has been valued as a book of Shinto gods.
In 1773, Katsutaka NASA wrote a book titled "Gisai". In it, he criticized "Koji Shui" as just depicting the Inbe clan who had been complaining about their state and filing a petition. Norinaga MOTOORI, who opposed to this view, wrote a book titled "Gisaiben" to defend it.
In the Modern Ages onwards, Sokichi TSUDA evaluated this book in his book "Research on Kogo Shui" in 1928 as being good enough to be treated as a history book of the time the book was written, but of little value as history records showing the times before Kojiki and Nihonshoki.
So far, this book has been regarded as being of less importance, when compared to the Kojiki and the Nihonsyoki. It is now being re-evaluated.