Kigo

Kigo (季語, "season word"^?) (plural kigo) is a word or phrase associated with a particular season, used in traditional forms of Japanese poetry. Kigo are used in the collaborative linked-verse forms renga and renku, as well as in haiku, to indicate the season referred to in the stanza. They are valuable in providing economy of expression.

Although the term kigo was coined as late as 1908, representation of, and reference to, the seasons has long been important in Japanese culture and poetry. The earliest anthology of Japanese poetry, the mid-8th century Man'yōshū, contained several sections devoted to the seasons. By the time of the first imperial Japanese anthology, the Kokinshū a century and a half later (AD 905), the seasonal sections had become a much larger part of the anthology. Both of these anthologies had sections for other categories such as love poems and miscellaneous (zō) poems.

The writing of the linked-verse form renga dates to the middle of the Heian period (roughly AD 1000) and developed through the medieval era. By the 13th century there were very set rules for the writing of renga, and its formal structure specified that about half of the stanzas should include a reference to a specific season, depending upon their place in the poem. According to these rules, the hokku (the opening stanza of the renga) must include a reference to the season in which the renga was written.

A lighter form of renga called haikai no renga ("playful" linked verse) was introduced near the end of the 15th century.Haikai was the linked verse practice followed and elevated by Matsuo Bashō and others until the Meiji period (1867–1912). Near the end of the 19th century, the hokku was completely separated from the context of haikai no renga by Masaoka Shiki and revised and written as an independent verse form which he named "haiku", though retaining the kigo. In the Taishō period (1912–1925) a movement began to drop the kigo entirely. Today most Japanese haiku include a kigo, though many haiku written in languages other than Japanese omit it (see for example Haiku in English).

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