During the Sekkanseiji Period (the period of Sekkan [regents and advisers] govern the country), most of the emperor's children except children by empresses demoted from nobility to subject; the requirements for conferring Ippon came to emphasized more on their relationship with the emperor and regents, and less on a career in Nihon.
摂関政治期になると、后腹以外の天皇の子女は臣籍降下する例がほとんどとなり、一品叙位の条件も二品の経歴よりも天皇や摂関との関係が重視されるようになった。