While travelling in an open coach through Edō in September 1867 the brothers were attacked by anti-foreign samurai from Numata, who, by drawing his sword, in a private vendetta was trying to enforce the Sonnō jōi policy.
His father was active in the Sonnō jōi movement, and Mutsu Munemitsu joined forces with Sakamoto Ryōma and Itō Hirobumi in the movement to overthrow the Tokugawa shogunate.
Joi Lansing | Joi Chua | Sonnō jōi | Joi Cardwell | Joi Baba Felunath | Adrienne-Joi Johnson | N-Joi | ''Michael W. Carroll by Joi Ito | Joi Ito | Joi |
There are speculations that he could have been a spy for the Chōshū Domain and that he also had close connections with Sonnō jōi groups in Mito and Tosa Province.