In Volume seven of the Kokin-Wakashu, eighteen wakas out of twenty-two gaka were made on the occasion of concrete celebrations of specific individuals (most of them for longevity, but some were for celebrating birth.), the author is not known for the first four wakas and they seem to have been made in an older time and under a situation which is not known.
ところで、古今和歌集巻七の賀歌22首のうち18首は、特定の個人の具体的な祝い（ほとんどが算賀だが出生慶賀もある）に際して詠まれたものだが、最初の4首は読み人知らずで、作歌年代も古いと見られ、歌が作られた事情もわからない。