In the midst of the political turmoil including an intensification of the Sonno Joi movement (the movement advocating reverence for the Emperor and the expulsion of foreigners) caused by the change from the national isolation to the opening of the country to the world as well as the dispute over shogun's successor between the Hitotsubashi group (which supported Yoshinobu TOKUGAWA) and the Nanki group (which supported Yoshitomi TOKUGAWA), the enlightened and farsighted daimyo (Japanese feudal lords) had been advocating the necessity of the political reform of the bakufu.
幕政の改革は、鎖国体制から開国への移行に伴う尊王攘夷運動の激化、将軍継嗣問題を巡る一橋派・南紀派の対立などの政治的混乱の中で、薩摩藩主・島津斉彬や越前藩主松平慶永ら、開明的な大名らの間ではつとに必要性を叫ばれていた。