is a form of Japanese poetry using only Chinese characters

Kanji

Kanji are the adopted logographic Chinese characters hanzi that are used in the modern Japanese writing system along with hiragana , katakana , Indo Arabic numerals, and the occasional use of the Latin alphabet...

 which was popular around 1770-1800. Kyōshi avoids typical poetic forms, and often includes humorous expressions and puns on alternate readings or meanings of the same characters.

Mostly written by low-ranking samurai and chōnin

Chonin

was a social class that emerged in Japan during the early years of the Tokugawa period. The majority of chōnin were merchants, but some were craftsmen, as well. Nōmin were not considered chōnin...

(townspeople), the form is closely related to kyōka, and to kyōbun, a form of prose writing which also uses only Chinese characters.

Ōta Nampo

Ota Nampo

was the most oft-used penname of Ōta Tan, a late Edo period Japanese poet and fiction writer. He wrote primarily in the comedic forms of kyōshi, derived from comic Chinese verse, and kyōka, derived from waka poetry...

is the most well-known of kyōshi poets; the form was very popular for a short time, but declined quickly and disappeared after the turn of the 19th century.