Japanese poetry has historically been governed by metric considerations based upon the tanka tradition. Free verse does away with the strict metrical structure of tanka, lending itself to the use of colloquial grammar and vocabulary. When Western examples of free verse entered Japan during the Meiji period, some Japanese poets saw free verse as a liberating form, with their adaptations and translations of Western free verse appearing in several anthologies, including Ueda Bin’s Kaichoon (The Sound of the Tide, 1905). The 20th century witnessed many fine Japanese free verse poets, including Takamura Kotaro, Ishikawa Takuboku, and Hagiwara Sakutaro.
Historical dictionary of modern Japanese literature and theater. J. Scott Miller. 2009.