Yoshinobu, Aizu and Kuwana Form the Ichikaisō Network

The appointment of Kuwana lord Matsudaira Sadaaki as Kyoto shoshidai in 1864 brought three prominent figures together in the capital: Hitotsubashi Yoshinobu, Aizu lord Matsudaira Katamori as Kyoto protector, and Sadaaki. Ichikaisō combines the first characters identifying Hitotsubashi, Aizu and Kuwana.

Their cooperation connected senior political direction with the protectorate and shoshidai’s responsibilities. Aizu and Kuwana supplied domain forces supporting their leaders’ work in Kyoto. The network dealt with the Kinmon conflict and Chōshū punishment while attempting to preserve cooperation between emperor and shogunate.

The six clauses of the later Satsuma–Chōshū agreement specifically named Hitotsubashi, Aizu and Kuwana as possible obstacles to advocacy at court. Its fifth clause contemplated armed confrontation if they blocked that work. This identifies the network’s political importance more closely than treating it as another name for the whole bakufu. The three participants held distinct offices and domain interests, and their Kyoto partnership became a target for opponents seeking different access to imperial authority.