It is necessary to take into consideration that there should be no records of previous generations, except for records of those that survived the Genpei War and became bushi during that period, gokenin during Kamakura period, those who participated in the Genpei War, and followers of a lower ranked officer in some shoen.
源平の争乱を生き抜き、少なくともその時期に武士となり、鎌倉時代に御家人、源平の争乱となった者、一部の荘園の下司について以外に、後世に記録が残っていないことを考慮する必要がある。