The thirty volumes of the Chronicles of Japan (J. Nihon shoki), completed in 720 (Yōrō 4), comprise Japan's oldest imperially commissioned historical document. Recorded chronologically in classical Chinese (J. kanbun) are events from the mythical age of the gods (J. jindai) through the eighth month of the eleventh reign year of Empress Jitō (645-702, r. 686-697) in 697.
Since explications of the Chronicles of Japan were a vital part of the life of the imperial court, many copies were produced. There are about ten extant early editions, which are generally classified into two categories—editions that were either passed down in or related to the Urabe family and those that were not. Examples of the first type include the Kanekata edition in the Kyoto National Museum, transcribed in 1286 (Kōan 9), and the Kanenatsu edition in the collection of Tenri University Library, dating from 1303 (Kengen 2), both of which chronicle the "Age of the Gods." Of the second type include this ninth-century work from the Nara National Museum, known as the Tanaka edition, as well as the Iwasaki edition in the Kyoto National Museum, copied in the tenth to eleventh centuries and consisting of volumes 22 and 24, and the Maeda edition in the Maeda Ikutokukai collection, dating from the eleventh century and consisting of volumes 11, 14, 17, and 20. All the editions above have all been designated as National Treasures.
This manuscript of the Chronicles of Japan, Volume 10, "Chronicle of Emperor Ōjin," in its present state consists of nine sheets of paper, the first and last sheets having been lost. The scroll gives an account of the fifteenth ruler, Emperor Ōjin (270?-310), from the second to the forty-first year of his life. Here, celebrated events such as the visit of the scholar Wani, an envoy from the Korean kingdom of Paekche (4th-7th centuries) are recorded.
The calligraphy brushed in a graceful, regular script (J. kaisho) indicates an early Heian period (794-1185) date, making the Tanaka version the oldest extant transcription of the Chronicles of Japan. Moreover, this version—which has no punctuation marks or phonetic script (J. kana) to indicate readings for the characters—is highly valued as being faithful to the original work. In closely examining the contents, textual variations not seen in other versions, such as the rendering of Ōyamato Mokumanchi as simply Mokumanchi, can be found, indicating that transcriptional errors appeared in later copies.
On the back of this scroll is copied the Collected Writings of Kūkai (J. Shōryōshū). Judging from the calligraphic style, this text is considered to have been transcribed in the late Heian period, after this volume of the Chronicles of Japan had fallen into disuse.