After the Kamakura period, yusoku kojitsu became as specialist field and the subject of active research, leading to the authorship of books including those on ceremonies such as "Kinpisho" written by Emperor Juntoku, "Kemmu Nenchu Gyoji" written by Emperor Godaigo, and "Kuji kongen" (the Rules of Court) written by Kaneyoshi ICHIJO; those on the government system such as "Shokugensho" written by Chikafusa KITABATAKE; and those on clothing such as "Masasuke Shozoku Sho" (Masasuke's rule book on costumes) written by MINAMOTO no Masasuke.
鎌倉時代以降、専門分化して、研究が盛んとなり、儀式については順徳天皇の『禁秘抄』、後醍醐天皇の『建武年中行事』、一条兼良の『公事根源』、官職制度については北畠親房の『職源抄』、服飾については源雅亮の『雅亮装束抄』などの有職故実書が著された。