Tsutsumi Chūnagon Monogatari (堤中納言物語, "Tales of the Riverside Middle Counselor") is a post late-Heian period Japanese collection of short stories.
It is likely each story was written by different authors at various times and later collected together into a single text.
Ōsaka Koenu Gonchūnagon is known to have been composed in 1055 by Lady Koshikibu.
This is confirmed in volume 8 of Rokujō Saiin Utaawase (六条斎院歌合) which includes one of the poems from this story.
In addition, poems from Hanazakura Oru Shōshō, Hodohodo no Kesō, Kaiawase, and Haizumi are included in the 1271 Fūyō Wakashū indicating an upper bound for these stories.