Who they were
Born in 1836 into a low-ranking samurai family of Tosa, he left his domain — then a crime — and studied under Katsu Kaishu, the shogunate’s naval modernizer.
What they did
In Nagasaki he founded a trading and shipping company, the Kameyama Shachu (later the Kaientai), often called one of Japan’s first modern companies. In 1866 he brokered the once-unthinkable Satsuma–Choshu alliance, which doomed the shogunate.
His eight-point program, the Senchu Hassaku, sketched a post-shogunal state and influenced the peaceful return of power (Taisei Hokan, 1867).
Legacy
He was assassinated in Kyoto in December 1867, at age 31; the killers’ identity is still debated, though the Mimawarigumi are usually credited. He remains the romantic modernizer-hero of the Restoration — an image boosted by Shiba Ryotaro’s postwar novel.