Although the Rōshigumi was funded by the Tokugawa Bakufu, the leader Kyokawa Hachirō and others had strong loyalties to the emperor and planned to gather other rōnin in Kyoto to combat insurgents in the city.

On March 26, 1863, Kiyokawa led the Rōshigumi out of Edo as the vanguard of Shogun Iemochi's procession to Kyoto, where they arrived on April 10, 1863.

One cause of the war was Emperor Meiji's declaration that he would decree the abolition of the 200-year-old shogunate and impose direct command by the imperial court.

Military action by the imperial forces and acts of violence by Meiji supporters in Edo led the Shogun Tokugawa Yoshinobu to attack and attempt to gain control of the court in Kyoto.

[3] Historical records indicate that, during the Boshin War, Nakazawa Koto defended the shogunate against the attack of the Satsuma and Ogi clans (the Satchō Alliance) in Edo in 1868.