In September 764, it was secretly informed that the Daishi (Daijo-daijin [Grand Minister]), FUJIWARA no Nakamaro (EMI no Oshikatsu) would raise a rebellion, and the Retired Empress Koken sent Shonagon (lesser councilor of state), Prince Yamamura to Chuguin (the Imperial Palace) of the Emperor Junjin who was in the Nakamaro's fact, and caused Yamamurao to collect gyokuji (the jewelry emperor's seal) and ekirin (literally, a station bell) which were necessary for exercising the right of the emperor.
天平宝字8年（764年）9月、太師（太政大臣）藤原仲麻呂（恵美押勝）が謀反を起こすという密告があり、孝謙上皇は仲麻呂派の淳仁天皇の中宮院（御所）に少納言山村王を遣わし、皇権の発動に必要な玉璽と駅鈴を回収させた。