Kunuhi were granted the status of kanko upon reaching the age of 66 or becoming disabled, and kanko would be freed as ryomin (upper class) upon reaching 76 years of age (80 for those related to a rebel).
官奴婢の年66歳以上および廃疾の者は官戸とされさらに官戸は76歳以上になると（反逆縁座は80歳以上）解放されて良民となる。