Kagerō Nikki (蜻蛉日記?, The Mayfly Diary) is a work of classical Japanese literature, written around 974, that falls under the genre of nikki bungaku, or diary literature. The author of Kagerō Nikki was a woman known only as the Mother of Michitsuna. Using a combination of waka poems and prose, she conveys the life of a noblewoman during the Heian period.
Kagerō Nikki is often called The Gossamer Years in English, which is the title given to the first English translation by Edward Seidensticker. The term kagerō has three possible meanings: it may mean a mayfly; a heat wave; or a thin film of cobweb, which is the meaning proposed by English Orientalist Arthur Waley.
During the Heian Period, prominent families often collected and compiled their poems in a family collection, or kashū. It is likely that Fujiwara no Kaneie, her husband, asked the Mother of Michitsuna to create such a collection for their family. However, because she decided to add her own experiences along with the poems that she and Kaneie exchanged, Kagerō Nikki emerged. From the outset, the Mother of Michitsuna reveals her concerns by exploring the reality of her condition.
Kagerō Nikki focuses on the development of the Mother of Michitsuna's relationship with Fujiwara no Kaneie ("the Prince") and how these experiences affect her. The diary entries detail events of particular emotional significance, such as when Kaneie visits other women while she stays at home taking care of their son ("the boy"). The Mother of Michitsuna's deep feelings for Kaneie are apparent in the way her words take on a tone of inner anguish as Kaneie's visits dwindle.
In an attempt to find solace, the Mother of Michitsuna makes pilgrimages to temples and mountains of religious importance. She often expresses her desire to become a nun, but the effect that act would have on her son’s future plagues her mind and prevents her from ever taking Buddhist vows.