The generations from Emperor Ninken to Emperor Suiko is called the Kesshi-Judai (Ten Undocumented Sovereigns), and Shimotsumaki contains only issues such as a genealogy and few specific issues, as well as Kesshi-Hachidai (Eight Undocumented Sovereigns).
仁賢天皇から推古天皇までは欠史十代ともいわれ、欠史八代と同じく系譜などの記述にとどまり具体的な著述が少ない。