For a simple overview, with examples:
The Golden Carousel of Life: Senryu:
Senryū (川柳, literally means 'river willow') is a Japanese form of short poetry similar to Japanese haiku.
The form is named after Edo era haiku poet Senryū Karai (柄井川柳, 1765-1838), whose collection Ifūyanagidaru (誹風柳多留) launched the genre (and hence his name) into the public consciousness.
Around a century after his death, senryu once again became prominent, as Ce Rosenow explains:
Although the Japanese poetic form, senryu, began more than two-and-a-half centuries
ago as an often bawdy form of verse focusing on human nature, it developed into a form that accommodated many aspects of the human experience. In the early twentieth century, Japanese immigrants in the United States began using senryu to document daily human activities in response to periods of cultural upheaval. In doing so, they instigated a tradition that continues in English-language senryu to this day.
[V]aried traditions of senryu certainly have been sustained in order to address the vicissitudes of human experience.
Written in the Face of Adversity: The Senryu Tradition in America by Ce Rosenow
Visiting Assistant Professor of Literature at the University of Oregon’s Clark Honors College USA.
Literary Imagination, Volume 12, Issue 2, 1 July 2010, Pages 210–228
Senryu are short aftertastes like amuse-gueule, or small arms visual gunfire, and potent as longer satirical poems.
But they can also be bittersweet, ironic, poignant, truthful, painfully revealing verses and I feel think honesty has an even higher register in senryu, if thoughtfully done. Senryu verse can act as vital checks and balances in our own lives: It feeds a need of a different place than haiku.
Alan Summers from:
Pieces of Her Mind: Women Find Their Voice in Centuries-Old Forms
Omega Publications (2012) ISBN-10: 0985035064 ISBN-13: 978-0985035068