For 10 points, name this country of origin of the renga and haiku.
Many poems from this present-day country interweave earlier poems without attribution in the "allusive variation" technique. Poets from this country collected lists of place names that they could instantly invoke to create a web of emotions and associations. Two- or three- measure punning or metaphorical introductions known as "preface phrases" open several poems from this country. Participants were divided into left and right groups, and submitted lyrics on pre-announced themes, in poetry contests from this country. An anthology whose name means Collection of (*) Ten Thousand Leaves, dating to the mid-eighth century, is this country's oldest book of poetry. In a popular format from this country, two or more poets alternated writing up to a hundred verses. A form of poetry from this country contains a seasonal reference, a transitional "cutting word," and seventeen morae, arranged 5-7-5. For 10 points, name this country of origin of the renga and haiku. 
Many poems from this present-day country interweave earlier poems without attribution in the "allusive variation" technique.
Japan [or Nippon-koku; or Nihon-koku] 