In 1867, Gengo was assigned to a fleet of small ten-person warships. That same year, the of the Royal Navy arrived at the warship training center, and as the training began on November 5, he became the head of the warship training center and also served as a student councilor on November 26. The Boshin War began when Imperial forces clashed with the Bakufu troops at Toba-Fushimi.