The Japanese tanka is a thirty-one-syllable poem, traditionally written in a single unbroken line. A form of waka, Japanese song or verse, tanka translates as "short song," and is better known in its five-line, 5/7/5/7/7 syllable count form.
One of the oldest Japanese forms, tanka originated in the seventh century, and quickly became the preferred verse form not only in the Japanese Imperial Court, where nobles competed in tanka contests, but for women and men engaged in courtship. Tanka’s economy and suitability for emotional expression made it ideal for intimate communication; lovers would often, after an evening spent together (often clandestinely), dash off a tanka to give to the other the next morning as a gift of gratitude.
In many ways, the tanka resembles the sonnet, certainly in terms of treatment of subject. Like the sonnet, the tanka employs a turn, known as a pivotal image, which marks the transition from the examination of an image to the examination of the personal response. This turn is located within the third line, connecting the kami-no-ku, or upper poem, with the shimo-no-ku, or lower poem.
Many of the great tanka poets were women, among them Lady Akazone Emon, Yosano Akiko, and Lady Murasaki Shikibu, who wrote The Tale of Genji, a foundational Japanese prose text that includes over 400 tanka. English-language writers have not taken to the tanka form in the same way they have the haiku, but there are several notable exceptions, including Amy Lowell, Kenneth Rexroth, Sam Hamill, Cid Corman, and Carolyn Kizer.
There are many excellent anthologies of Japanese verse, most of which feature lengthy selections of tanka. Rexroth's translations, which include One Hundred Poems from the Japanese and One Hundred More Poems from the Japanese, are considered classics, and The Ink Dark Moon: Love Poems by Ono no Komachi & Izumi Shikibu, translated by Jane Hirshfield with Mariko Aratani, continues this tradition.
Edward Hirsch also writes about the tanka in his book A Poet’s Glossary (Harcourt, 2014):
tanka: Also called uta or waka. The character for ka means “poem.” Wa means “Japanese.” Therefore, a waka is a Japanese poem. Tan means “short,” and so a tanka is a short poem, thirty-one syllables long. It is unrhymed and has units of five, seven, five, seven, and seven syllables, which were traditionally printed as one unbroken line. In English translation, the tanka is customarily divided into a five-line form. The tanka is sometimes separated by the three “upper lines” (kami no ku) and the two “lower ones” (shimo no ku). The upper unit is the origin of the haiku. The brevity of the poem and the turn from the upper to the lower lines, which often signals a shift or expansion of subject matter, is one of the reasons the tanka has been compared to the sonnet. There is a range of words, or engo (verbal associations), that traditionally associate or bridge the sections. Like the sonnet, the tanka is also conducive to sequences, such as the hyakushuuta, which consists of one hundred tankas.