Dan no Ura Yoru no Kassenki (壇ノ浦夜合戦記)
Dan no Ura Yoru no Kassenki is the title of a Japanese classic pornographic novel. The story line revolves around a love affair between MINAMOTO no Yoshitsune and Kenreimonin, who threw herself into the sea and was rescued during the Battle of Dan no Ura.
It is suggested that Sanyo RAI was the author of this book, but there is a high likelihood that it was written by another person under the guise of Sanyo. The novel was originally written in Chinese.
During the Battle of Dan no Ura, TAIRA no Tokuko (Kenreimonin) was rescued against her will. To console Tokuko, Yoshitsune held a banquet giving a feast to his vassals and Tokuko's court ladies. After the banquet, Yoshitsune was alone with Tokuko and successfully began an affair with her using his charm.
The reason this story about an affair between Yoshitsune and Kenreimonin appeared is due to it being mentioned in 'Genpei Seisuiki' (The Rise and Decline of the Minamoto and Taira Clans). During the Edo period, the story became well known even among the general public and a number of kyoka (comic tanka (satire)) were written using the affair as a subject. It is unknown as to whether or not the affair was historical fact, however, as there is virtually no credibility to the story.