In the tenth century, however, these influential families obtained fuyu no ken (the right of tax exemption) by Daijokanpu (official documents issued by Daijokan, Grand Council of State)/Minbushofu (official documents issued by Minbusho, Ministry of Popular Affaires) and converted their shoen into fuyusoden in effect.
しかし、10世紀に入ると権門が太政官符・民部省符によって不輸の権(日本)を獲得して，所有する荘園を事実上の不輸租田とした。