To control the name list of Imperial families, princes were often appointed to Kami, who was an administrator, during the Nara period and after the Heian period the Shirakawa family (Kazan-Genji [Minamoto clan], the Hakuo family) were appointed for generations.
皇族の名簿を管理するため、長官の正には奈良時代には王が任命されることが多く、平安時代以後は代々白川家（花山源氏・伯王家）が任じられた。