 Scholarship on the "Kujiki" generally considers it to contain some genuine elements, specifically that Book 5 preserves traditions of the Mononobe and Owari clans, and that Book 10 preserves the earlier historical record the "Kokuzō Hongi".Ten volumes in length, it covers the history of ancient Japan through Empress Suiko, third daughter of Emperor Kinmei.The preface is supposedly written by Soga no Umako (+626).