Iwasaki Yatarô was a gôshi from Tosa who headed the domain’s trading business in Nagasaki during the waning days of the Tokugawa shogunate. He became a business associate of Sakamoto Ryôma through the Kaientai trading operations. Iwasaki was not particularly fond of Ryôma but "business was business". Iwasaki later formed the famous Mitsubishi Trading House and became one of Japan’s most successful businessmen of the Meiji period. His many philanthropic projects included the restoration of Rikugien, the Edo period gardens of daimyô Yanagisawa Yoshiyasu.
- Hillsborough, Romulus. RYOMA- Life of a Renaissance Samurai. Ridgeback Press, 1999
- Jansen, Marius B. Sakamoto Ryoma and the Meiji Restoration. Columbia University Press, 1994.
- Gallery labels, Tôyô Bunko.