Yoshida Shōin
In 1853, when Yoshida Shōin was convicted for attempting to stow away on one of Perry's ships, Sakuma was also sentenced by association to house arrest (), which he endured for 9 years. During the arrest, he continued to study Western sciences, and developed various electric machines based on the elekiter and the Daniell battery, Japan's first seismometer, as well as improvements to guns. After his release, Sakuma Shozan emphasized that the only solution to the country's conflicts was to move the Imperial court from Kyoto to Hikone Castle, and continued to advocate opening Japanese ports to foreign traders, as well as reinforcing the Bakufu through collaboration with the Imperial administration (Kōbu gattai).