The Shimousa Sakura domain (present Chiba Pref., east of Tokyo) is a representative domain in
hereditary vassalage to the Tokugawa family in the Edo period (1603-1867). For its frequent changes of the fief (transfer of the clan governing area ordered by the Tokugawa Shogunate to make the clan a less powerful competitor to the Government), the clan family kept large volumes of records. The records are classified into the matters related to its inter-clan government, that is, the fief, clan masters, vassals, clan government, finances, diaries, and the diplomacies in Tokugawa
Shogunate, the clan's relationships with the Shogunate and others.
Masayoshi Hotta (1810-1864) the clan master at the end of the Edo period, was a competent
government official who was in charge of the diplomatic administration in the Shogunate amidst the utter political confusion caused by the visit of Admiral Perry. Thus the records also contain
many materials concerning the diplomatic history at the end of the Edo period.