"Eikyoki" is an account of war that covers the incidents ranging from the Eikyo War and Yuki War in the Muromachi period to the political circumstances in Togoku (the eastern part of Japan, particularly Kanto region). Confirmed by various historical materials, the contents are said to be accurate and reliable, so it has often been used for the study of history until today.
Both the year of completion and the author are unknown, but it was revealed that various war records concerning Eikyo War and Yuki War were based on the military record, "Kamakura Mochiujiki." The relevant part of "Eikyoki" is said to be a rewrite of "Kamakura Mochiujiki." It is considered a true record of war which was written fairly without much embellishment. However, it has a tendency to praise Kanto Kanrei (a shogunal deputy for the Kanto region) Norizane UESUGI as a loyal retainer.
There is an account of war called "Yuki Senjoki" (the record of Yuki War), which has almost the same contents as "Eikyoki," and is considered one of the denpon (existent books of transcription and published books). Comparing "Eikyoki" with "Yuki Senjoki," the latter is regarded as a good manuscript which is closer to the original.
However, the relationship between these two records has not necessarily been established, and sometimes both names are written down together like this: 'Eikyoki (Yuki Senjoki).'
Most denpon such as "Eikyoki" and "Yuki Senjoki" began with a genealogy of the Ashikaga clan, which is followed by details of Eikyo War and Yuki War, restoration of Kamakura bakufu (Japanese feudal government headed by a shogun), the Takamigahara Battle in which the Yamanouchi-Uesugi clan and the Ogigayatsu-Uesugi clan fought during the Chokyo Rebellion, and the appearance of Soun HOJO. However, it is pointed out that the original book consisted of 14 volumes in total ending with 'Koga Castle incidents,' and the chapters after 'Dokan OTA incidents' were probably inserted later based on "The Record of Dokan OTA."