In 1858, when the Imperial court and the Edo bakufu (Japanese feudal government headed by a shogun) had an disagreement over an imperial sanction for the Treaty of Amity and Commerce between the United States and Japan, he was persuaded by statesman of the Mito clan and the Fukui clan to disagree on the Emperor's sanction for the treaty and to agree with the Hitotsubashi group on the successor matter of Seii taishogun (literally, "great general who subdues the barbarians").
安政5年（1858年）、日米修好通商条約締結への勅許をめぐり、朝廷と江戸幕府が対立するにおよび、水戸藩や福井藩の藩士に説得され、条約勅許不同意および征夷大将軍継嗣問題における一橋派の意見に同意する。