In the unsettled period after to ending of the national isolation policy, the political situation in Japan became increasingly chaotic.
Anti-government and anti-foreign rōnin congregated on the old imperial capital of Kyoto, and many of the daimyōs from the western feudal domains also established residences in Kyoto in an attempt to exert influence on the Imperial Court to pressure the shogunate towards the sonnō jōi movement ("Revere the Emperor, Expel the Barbarians") against the foreign powers.
However in the evening, Tokugawa Yoshinobu, accompanied by the daimyōs of Aizu and Kuwana, slipped away from Osaka Castle and headed to Edo.
In June, the Meiji government decided to move the Tokugawa family to the Sunpu Castle in Suruga (present day Shizuoka).
Even after their unit's disbandment, Imai Noburō and others would continue to fight alongside the Shogunate remnants of the forces against the Imperial Army.