In 1177, he participated in a plot planned by FUJIWARA no Narichika and Saiko to overthrow the Taira clan, for which a secret meeting was held at Shunkan's mountain villa in Shishigatani (however, according to "Gukansho" (Jottings of a Fool), the secret meeting was held at a mountain villa of Joken, son of Shinzei).
1177年、藤原成親・西光らの平氏打倒の陰謀に加わって鹿ヶ谷の俊寛の山荘で密議が行われた（ただし、『愚管抄』によれば、信西の子・静賢の山荘で密談が行われたとされている）。