The (), also shortened to (), were imperially-commissioned Japanese anthologies of waka poetry. They numbered 21 in total (called nijà «ichidaishà «).
The term (hereafter shortened to ) refers to anthologies of waka poetry compiled and presented for inspection on the order of either a reigning emperor of Japan, or a retired or cloistered emperor. The first was the Kokin Wakashà « compiled at the beginning of the tenth century and the last was the Shinshoku Kokin Wakashà « compiled in the first half of the fifteenth century, with 21 in total.
The first three are referred to as the sandaishà «, the first eight (through the Shin-Kokin Wakashà «) as the hachidaishà «, the ninth (the Shin Chokusen Wakashà «) through the 21st called the jà «sandaishà «, and the whole group of 21 as the nijà «ichidaishà «. The total number of poems contained in the 21 collections comes to about 33,700.
Two collections were compiled on the orders of emperors but are not included in this list. The first is the Shoku-Shika Wakashà « (compiled in the late 12th century by Fujiwara no Kiyosuke), which was commissioned by Emperor Nijà Â, but the emperor died before it could be presented to him, and so it was never formally given the title of . The second is the Shin'yà  Wakashà «, a so-called , which was compiled at the end of the 14th century at the Southern Court.
The are Japan's twenty one imperial collections () of waka poetry written by noblemen. The following texts listed in chronological order constitute the Nijà «ichidaishà «:
The Hachidaishà « are the first eight collections, in which the first three collections are the Sandaishà «. The Sandaishà « provided both the language and organizational principles for the rest of the anthologies thereafter. They are:
The Jà «sandaishà « are the later thirteen collections. They are:
Note that the Shin'yà  Wakashà «âÂÂalthough an imperial anthology of Japanese poetryâÂÂis not included in the list of twenty one collections.
The compilers of the first several were acting under direct orders of the reigning emperor, but during the period of cloistered rule (or rather the later Heian period and the Kamakura period) it was more common for the anthologies to be commissioned by the retired emperor who was in charge of the court (the Daijà  Tennà Â).
With the exceptions of the Shà «i Wakashà « and the Fà «ga Wakashà «, the commissioner would give the order to between one and five compilers to select poems, arrange them into books by topic, arrange the poems within each book and make orthographic decisions. When the compilation was completed, the collection would be presented to the commissioner for inspection. Occasionally the commissioner would order changes to be made, resulting in, for example, the three variant texts of the Kin'yà  Wakashà «. The Shin-Kokin Wakashà « has an unusual history that after being inspected and approved, later changes were made personally by the commissioner.
The last four were compiled during a period of decline for the imperial house, and were instead commissioned and completed under the auspices of the Ashikaga shà Âguns. Ashikaga Yoshimasa ordered a further collection, which Asukai Masachika (é£Âé³¥äºÂé 親) began compiling, but the work was abandoned during the à Ânin War.