In this year, Ryoma achieved a crucial mission entrusted by Toshimichi OKUBO and Takamori SAIGO to deliver an OKUBO's letter, which is famous for its phrase, "Unjustifiable Imperial order is not Imperial order," to the Choshu clan's high-ranking official. "Politics in the End of Edo Era and Satsuma Clan" by Suguru SASAKI (Yoshikawa kobunkan, 2004).
この年、「非義勅命は勅命にあらず」という文言で有名な大久保利通の書簡を、長州藩重役に届けるという重大な任務を龍馬が大久保や西郷隆盛に任されている。佐々木克『幕末政治と薩摩藩』（吉川弘文館、2004年）。