 During the Anglo-Satsuma War of 1863, he fought alongside Ōyama Iwao and Saigō Tsugumichi.After the end of the conflict, he was sent to Edo, and then to Hakodate, where he was ordered to study "rangaku" and western customs under Takeda Ayasaburō.He then went to Yokohama to learn English from Samuel Robbins Brown.