When Kintsune was caught by Retired Emperor Gotoba immediately before the Jokyu War, Nagahira secretly sent a messenger to the Kamakura bakufu (Japanese feudal government headed by a shogun) to inform that the Retired Emperor killed Kyoto military governor Mitsusue IGA and schemed to raise an army.
承久の乱開戦直前に後鳥羽上皇によって公経が囚われると、秘かに鎌倉に使者を送って、上皇の挙兵計画と京都守護伊賀光季の殺害を知らせた。