After the era of Emperor Gokomyo, although the basic rule for Imperial succession was for a male Imperial member to succeed to the throne, there were some female Empresses that temporarily succeeded, in case the other candidates were too young to become Emperor.
後光明以降は、直系男子への継承を基本として、継承者が未成人などの場合に中継ぎとしての女帝が擁立されていた。