On October 14, 764, soon after she received an anonymous lead about the rebellion by Dajo-daijin (the Grand Minister) EMI no Oshikatsu (he was also called FUJIWARA no Nakamaro), Empress Koken sent Prince Yamamura to Chuguin, where Emperor Junnin was, and she had him collect the Imperial Seal and the Ekirei bell, which were needed to exercise imperial power.
天平宝字8年（764年）9月11日、太政大臣恵美押勝（藤原仲麻呂）が謀反を起こすとの密告があり、孝謙天皇は山村王を淳仁天皇の居る中宮院に派遣して、皇権の発動に必要な玉璽と駅鈴を回収させた。