Although until the first stage of the Kamakura period new 'families' were produced as their young people established branch families, in the latter stage making new branch families became difficult due to economic factors and so forth; various suits arose, including ones between a legitimate child and a child born out of wedlock in regard to the succession of existing estates.
鎌倉時代前期までは、公家の子弟が分家することによって新たな「家」が生み出されることが行われてきたが、後期に入ると経済的理由などから分割が困難となり、既存の家領の継承を巡って嫡子と庶子の争いなど各種の訴訟が生じるようになった。