Cooped into dark room
Afraid to walk on wet streets
One more day I rest
Rains slide playfully outside
Weaving slippery green grounds
Originating in ancient Japan, a tanka (ton’- kah;) consisted of a haiku sent by mail or messenger and a two-line reply added to it for the returned message. Now tankas are composed in their final, familiar five-line format.
You may recall that haiku does not rhyme and consists of 17 syllables in three lines in a 5–7–5 format (five syllables in line one, seven in line two, then five again). A tanka adds two unrhymed lines of seven syllables each, for a total of 31 syllables. It can be in the 5-7-5-7-7 or in the two-stanza 5-7-5 ... 7-7 format.
Since they are short, titles of tankas may be taken from the poem’s first line or a key line, or are simply numbered, though naming poems is completely up to the author without specific rules.