Kyuji (A Record of Stories Current at Court) (旧辞)
"Kyuji" is regarded to be a history book handed down by each clan, which was used as basic information for editing "kiki" (the Kojiki and Nihonshoki), but it was lost and is not existent, just like "Teiki" (a genealogy of the imperial family).
"Sendai no kuji" (Ancient matters of former ages) and "Honji" (Accounts of origin) in the introduction of "Kojiki" (The Records of Ancient Matters), and "Joko shoji" (matters of high antiquity) in the section of Emperor Tenmu's 10th year and 3rd month in "Nihonshoki" (Chronicles of Japan) are considered to be this book.
There is a theory that "Teiki" and "Kyuji" were not separate books but a unified book.
Sokichi TSUDA regarded that 'Kyuji' had become the original of the narrative and mythological part in the description of the kiki.
Since the narrative part of Kojiki ends around the description of Emperor Buretsu and the rest of the description was almost solely about genealogy and the description of Nihonshoki also changes its nature hugely at around this point from the mostly narrative description with few specific dates to the description mostly based on the records with dates, he regarded the contents of 'Kyuji' to have ended around this, and that 'Kyuji,' which had been handed down orally, was documented in the 6th century right after that. This theory is now generally accepted, but as far as the introduction of Kojiki is strictly read, even though the work for making the history book was done both with Teiki and Kyuji, Kojiki itself is supposed to have only Kyuji from Teiki and Kyuji in its contents. There is an opinion that the current and common 'general understanding on Teiki and Kyuji; that is, 'Teiki has genealogy in its contents, and Kyuji narratives,' does not make sense, if the current Kojiki includes both genealogy and narratives. There is another opinion that the 'common name' which is regarded as a generic name of more than one book or document meeting certain requirements such as "Kyuji" each family owns should be clearly differentiated from the 'proper name' which is regarded to refer to the certain books edited at the certain point such as "Sendai no kuji" and "Chokugo no kuji" (Records of ordinances). And since two history books, "Teiki" and "Kyuji" are mentioned alongside each other in most cases, having slightly different names in the introduction of "Kojiki" or others, there is an opinion that these were not simply mentioned alongside each other, but united originally for being combined, and that there might have existed a form we can call 'Japanese style Kidentai (biographical historiography),' different from Chinese Kidentai combining two history books.