Polymath 682 - 7a

[Geoff.T]

Hi everybody
Grid sorted and all finished except for 7a.
To my way of thinking there are two possible answers here, both satisfying clue. I'd be interested to hear other's comments.
Geoff

[dannyk13]

What is the clue?

[Lie-in King]

Hi Danny -

7a Type of Japanese poetry (5) ?A?K?

[foxwall]

Type of Japanese poetry. I've got haiku, but my knowledge of Japanese poetry is pretty limited........

[Mamyalynne]

There is another that fits the pattern, they should therefore accept both.

[Lie-in King]

'Tanka' is another - IMO, either should be acceptable, considering this hasn't been the Polymath's finest hour...

[maeva]

i also have haiku, but tanka should be accepted