It contains excellent poems that had not been selected for the successive Chokusenshu (anthologies of poems collected by imperial command) and poems composed by the contemporary poets; the oldest poems were made during 990 to 995 (in fact, the beginning of the period from 987 and 989), the reign of the Emperor Ichijo.
一条天皇朝の正暦年間（実は永延の始め）を上限に、代々の勅撰集に漏れた秀歌や、当代の歌人の作品を収める。