When the Onin War broke out Yoshizane sided with the Eastern Camp due to the fact that the cousin of his wife was Katsumoto HOSOKAWA of the Eastern Camp, putting himself against Yoshifuji KIRA sided with the Western Camp; when Yoshifuji left Kyoto to Mikawa Province, Yoshizane appointed his son Yoshinobu KIRA in charge of protecting Kyoto, and departed to Mikawa on May 18, 1467 for tracking down Yoshifuji ("Miscellaneous Records of the Daijo Temple and Shrine").
応仁の乱が起こると、義真は妻の従兄弟が細川勝元という関係から東軍に属し、西軍についた吉良義藤と対立、義藤が三河国に下向すると、これに対応するため京都を息子の吉良義信に任せ、応仁元年（1467年）5月18日に三河に向けて出立した（『大乗院寺社雑事記』）。