Shibocho unearthed from the Remains of Akita-jo Castle was the first one showing a series of information such as Kabane (hereditary title), head of Ko (smallest social organization unit in provincial administration), name of deceased person, age, classification, and date of death.
姓、戸主、死亡者名、年齢、区分、死亡月日の一連の情報がわかるものとしては秋田城跡の例が最初である。