Oyudono no ue no nikki (Daily Records of the Honorable Lady of the Imperial Office of Housekeeping) (御湯殿上日記)

Oyudono no ue no nikki (Daily Records of the Honorable Lady of the Imperial Office of Housekeeping) is a daily record that was kept through the years by lower-ranking court ladies at the Imperial court. It is said that there was an anteroom for lower-ranking court ladies beside the imperial bath chamber in the Imperial court, and that the daily records were located in that room. It was written in turns by lower-ranking court ladies on duty, written in women's writing (kana). It is said that there are also a few rare parts written by the emperor himself instead of them.

Although in a sense it was originally a secret diary of the Imperial court (a confidential record) and a private one, sometimes a manuscript was made for future reference, and that is why most of the records for 350 years, from 1477 (in the Muromachi period) to 1826, still remain when adding up the original documents, manuscripts and abridgments, even though parts of them in the middle are missing. It is a rare historical source, especially when considering that the records from the Sengoku Period (Period of Warring States) (Japan), a time of especially fierce fighting, still exist. It is also valuable material for the field of the study of the writing and language used by women in the Imperial court (court ladies' language).

Although the crux of the description is mainly the emperor's daily activities, the records also include topics that do not appear on the center stage of politics; articles about events in the Imperial court such as court ceremonies, conferrals of rank and office, imperial grants and tribute, and trends among the Imperial family or court ladies, etc. Since the diary of 1598 was included in the "Gunsho ruiju" (Classified Collection of Japanese Classics), it has garnered attention as an original source for the history of the Imperial court and political history.