Kasen

Renku (連句^?, "linked verses"), or haikai no renga (俳諧の連歌^?, "comic linked verse"), is a Japanese form of popular collaborative linked verse poetry. It is a development of the older Japanese poetic tradition of ushin renga, or orthodox collaborative linked verse. At renku gatherings participating poets take turns providing alternating verses of 17 and 14 morae. Initially haikai no renga distinguished itself through vulgarity and coarseness of wit, before growing into a legitimate artistic tradition, and eventually giving birth to the haiku form of Japanese poetry. The term renku gained currency after 1904, when Kyoshi Takahama started to use it.

The oldest known collection of haikai linked verse appears in the first imperial anthology of renga, the Tsukubashū (1356–57).

Traditional renga was a group activity in which each participant displayed his wit by spontaneously composing a verse in response to the verse that came before; the more interesting the relationship between the two verses the more impressive the poet’s ability. The links between verses could range from vulgar to artistic, but as renga was taken up by skilled poets and developed into a set form, the vulgarity of its early days came to be ignored.

Haikai no renga, in response to the stale set forms that preceded it, embraced this vulgar attitude and was typified by contempt for traditional poetic and cultural ideas, and by the rough, uncultured language that it used. The haikai spirit, as it came to be called, embraced the natural humor that came from the combination of disparate elements. To that end haikai poets would often combine elements of traditional poems with new ones they created. A well-known example of this early attitude is the opening couplet, possibly by Yamazaki Sōkan (1464–1552), from his Inutsukubashū (犬筑波集, "Mongrel Renga Collection").

...
Wikipedia