For that reason, not only "houses with diaries" but all of aristocratic society during the medieval period depended on these diaries which each successive generation inherited as the 'foundations of knowledge,' and took the diaries to be the principal source for determining house territory and property, which was each family's 'economic base'; eventually the importance of these diaries as well as instructions on how to handle diary-related matters came to be recorded in such documents as the letter of transfer and the last will and testament given to each successor (the eldest son and heir) of each such family.
そのため、中世の公家社会においては日記の家に限らず、その家に相伝された家記は「知識的基盤」として、「経済的基盤」である家領とともに家産の主要部分とされ、その家の後継者（嫡男）に充てられた譲状・置文などによってその重要性や取り扱いについて記されるようになった。