In 1863, with the start of a big crackdown on the Sonno Joi (Revere the Emperor, Expel the Barbarians) movement in Tosa domain that followed the August 18 Incident (which falls on September 30 in the Gregorian calendar) in Kyoto, he quickly escaped the domain and in October of the same year, he sought refuge in Mitajiri, Choshu domain (now Hofu City).
文久3年（1863年）、京都での八月十八日の政変後に土佐藩内でも尊王攘夷活動に対する大弾圧が始まると、速やかに藩を脱藩し、同年9月、長州藩三田尻（現防府市）に亡命する。