Since secession (of a prince) from the Imperial Family on October 14, 1947, all the Miyake family used their Miya go title as their 'surname' when complying with the Family Registration Law, the same names like Yamashina, Kuni, and Fushimi who were previously demoted from nobility to subject were used as their surnames.
1947年（昭和22年）10月14日の皇籍離脱では、全ての宮家で宮号をそのまま戸籍法上の「氏」としたため、かつて降下した山階家・久邇家・伏見家と戸籍法上の氏が重複することとなった。