This is partly because that, on September 15, the Japanese government decided to dispatch envoys to Tang China and, at the same time, appointed high-ranking officials of the Imperial Court to regional military governors of the Tokai-do Road, the Tosan-do Road, the Sanin-do Road, and the Saikai-do Road.
というのも8月18日(旧暦)には遣唐使発遣が決定され、同時に朝廷の高官が東海道、東山道、山陰道、西海道各道の節度使に任命された。