The book was written by FUJIWARA no Teika of the Mikohidari family who had had a chance to secretly read commentaries on "Kokin Wakashu" originally made by Kensho of the rival Rokujo Toke (Rokujo Fujiwara family), who transcribed the commentaries in its first volume of the Spring Poetry part and added his own reviews (based on the Mikohidari family's poetry school established by FUJIWARA no Toshinari) as 'mikkan' (personal views), to thereby complete his own version.
元は六条藤家の顕昭によって書かれた『古今和歌集』の用語に対する注釈書を対立関係にあった御子左家の藤原定家が秘かに見る機会を得て春歌上巻の部分を写し、これに自説（藤原俊成以来の御子左家の歌道家学）を「密勘」として書き加えた物である。