Besides being an important early study of
Nihon Shoki, it also includes many full citations from other historical texts, some of which are no longer extant. These include
Jōgūki,
Nihongi Shiki,
Kogo Shūi,
Tensho,
Sendai Kuji Hongi, and more than thirty
fudoki. In addition, it is a valuable resource to supplement history missing from
Kojiki and
Nihon Shoki. The imperial genealogies are important since the genealogies that were once part of
Nihon Shoki have since been lost. For example, they clarify the genealogy for
Emperor Keitai which is lacking in the existing
Nihon Shoki. The collection of definitions and readings for old words are also linguistically valuable. ==See also==