Yoshida was Tosa daimyo Yamauchi Yodo’s most trusted and reformed-minded minister and was quite influential on other upcoming Tosa leaders such as Goto Shojiro and Itagaki Taisuke. By remaining loyal to the Bakufu, Yoshida drew the wrath of Takechi Zuizan and his Tosa Loyalist Party, and as a result, was assassinated on his way home from Kochi castle.
- Hillsborough, Romulus. RYOMA- Life of a Renaissance Samurai. Ridgeback Press, 1999
- Jansen, Marius B. Sakamoto Ryoma and the Meiji Restoration. Columbia University Press, 1994.