From Emperor of Japan: Meiji and His World, 1852–1912, by Donald Keene (Columbia U. Press, 2005), Kindle pp. 66-67:
The shogunate was faced with a dilemma. It clearly wished for better relations with the court, which necessitated obeying [Emperor] Kōmei’s injunction to expel the barbarians, but the most intelligent men in the shogunate—for example, Tokugawa Yoshinobu (1837–1913) and Matsudaira Yoshinaga (1828–1890)—were aware that opening the country was inevitable. The shogun probably had no alternative in the end but to reply to Kōmei in terms of assurances that he fully intended to carry out the principle of jōi [攘夷 Expel the Barbarians].
The change in the relative importance of the emperor and the shogun was quickly noticed by the leaders of the different domains, and many daimyos found it necessary to visit Kyōto. The shogunate had strictly prohibited them from entering the capital, and the normal route taken by daimyos on their way to Edo from the west of Japan skirted the city of Kyōto; but at this juncture the prohibition had lost force, and daimyos now called regularly in Kyōto. Indeed, the center of politics had moved from Edo to Kyōto. Profiting by the sudden increase in its importance, the court used the influence of the visiting daimyos to persuade the shogunate to change features in the system that it found objectionable. This was the first time in at least 500 years that the emperor possessed such political importance. The main thrust of court politics was not, however, aimed at securing greater power for the emperor but at achieving the goal of jōi.
The change affected the nobles as well. Until this time they had nothing to do with national politics; instead, their political concerns were restricted to the palace and its ceremonies. Now, however, nobles began to take an active part in the government, a step toward the restoration of imperial authority.
The new importance of the emperor was underlined in 1863 when the shogun visited the capital, the first time there had been such a visit in more than 200 years. [Shogun] Iemochi wished to demonstrate both his reverence for the court and his profound desire to achieve kōbu gattai [公武合体 Union of Imperial Court and Shogunate]. The shogun was preceded by his most important advisers, including Tokugawa Yoshinobu, who visited the palace on February 27 and was received by the emperor. Three days later, Yoshinobu called at the Gakushū-in, the school for sons of the nobility founded by Kōmei’s father. On this occasion he proposed that the old practice of requiring junior members of the imperial family to enter Buddhist orders be discontinued; instead, they should be named shinnō ([新王] princes of the blood) and allowed to remain in the laity. He also proposed that after many years of confinement in the Gosho [御所 Imperial Palace], the emperor should tour the country in the spring and autumn in the manner of the monarchs of olden times. Finally, he suggested that Prince Son’yu (who had been condemned to perpetual confinement during the Ansei purge) be allowed to return to the laity. All three proposals were calculated to ingratiate him (and the shogun) with the emperor.