The Mimurodo family was considered to be a branch line of the Yanagihara family originated from the Hino Family, descendent from the Manatsu line, the Hokke (Hoku Family) of the Fujiwara clan, and at first the family used the name 'Kitakoji' but in 1665, at the request of the family, it was allowed to change the family name to 'Mimurodo.'
三室戸家は藤原氏北家真夏流日野家柳原庶流とされ、初め北小路を称したが寛文5年（1665年）、願いにより三室戸を家名とした。