The mission was sent following the 1863 "Order to expel barbarians" (攘夷実行の勅命) issued by Emperor Kōmei, and the Bombardment of Shimonoseki incidents, in a wish to again close the country to Western influence, and return to sakoku status.
Nagaoki left with a mission of 36 men on a French warship, stopped in Shanghai, India, and Cairo through the Suez Canal.
He finally arrived in Marseille and then Paris, where he met with Napoleon III and with Philipp Franz von Siebold.
Nagaoki however was very impressed with the advancement of French civilization, and became very active in promoting the dispatch of embassies and students abroad, once he had returned to Japan.
Nagaoki brought many documents from France, related especially to physics, biology, manufacture, textiles and also fermentation technologies.