Six Assassins Kill Ōkubo Toshimichi at Kioichō

Ōkubo Toshimichi was killed on May 14, 1878, while traveling by carriage from his Tokyo home to the temporary imperial residence at Akasaka. The attack took place at Kioichō, before the carriage reached Kioizaka. Its six participants included five former samurai from Ishikawa and one from Shimane, led by Shimada Ichirō.

The conspirators emerged from networks of disaffected former samurai. Shimada and Chō Tsurahide had abandoned a plan for an uprising in Kanazawa and recruited accomplices for an assassination instead. After killing Ōkubo, the attackers went to the police and surrendered.

Their written justification had been commissioned from Kuga Yoshinao of the Chūkokusha political association. It criticized government policy, but its arguments cannot simply be treated as a common manifesto shared by every participant. Attempts to secure newspaper publication did not produce the immediate publicity the conspirators sought.

The killing removed a central government leader without reversing the state’s governing program. In 1879, Okamoto Kisen turned Shimada into the protagonist of a popular novel, adding fictional and romantic material to the account. That later story helped circulate the attacker’s name, while also introducing scenes that are not independent evidence of the assassination itself.