Kagero Diary (The Gossamer Years) (蜻蛉日記)

"Kagero Diary" is a diary of a female writer who lived during the Heian period. The author was the mother of FUJIWARA no Michitsuna. The diary describes the events that occurred from 954 to 974, and is thought to have been completed in or around 975. The diary consists of three volumes. The title was taken from a sentence in the diary: "When I think upon these fleeting things, I feel I do not even know if they really existed or not, and thus have named my diary the Kagero (gossamer) Diary."

Among other topics, she wrote of her married life with her husband FUJIWARA no Kaneie, her struggles with Kaneie's second wife Tokihime (the mother of FUJIWARA no Michinaga), and her husband's habit of taking one mistress after another. The diary also contains the records concerning her pilgrimage to the Karasaki, Ishiyama and Hase temples, friendships with the upper nobles, the loneliness caused by her mother's death, the growth and marriage of her son FUJIWARA no Michitsuna, and the marriage arrangement and cancellation of her adopted daughter, whom she took from MINAMOTO no Kanetada's daughter, the former wife of Kaneie.

The diary ends on New Year's Eve, when FUJIWARA no Michitsuna's mother is thirty-nine, just twenty years before her death.

She also describes her friendships with poets; in the diary are recorded some 261 waka.
The following poem which appears in her diary also was selected for inclusion in the Hyakunin Isshu (One Hundred Waka by One Hundred Poets): I lie alone, forlorn, and sigh throughout the night, waiting for the dawn; can you imagine just how long such nights feel?"
Her diary is considered a forerunner of the women's diary genre, and had a significant influence over a wide range of literary works, first and foremost the "Tale of Genji." The diary is also regarded as the precursor of self-reflective literature, in which writers objectively examine their own feelings and experiences.

Some scholars state that the diary was written in order to blame Kaneie or take revenge on him, but Yuichiro IMANISHI offered the opinion that it was a kind of propaganda that Kaneie helped to make because the diary contained many of his poems.