In 1858, for the purpose of serving as an instructor at the Rangaku school opened at the residence of the lord of Nakatsu domain in Edo, Yukichi went to Edo accompanied by Masao YOSHIKAWA (in those days, his name was Shukichi OKAMOTO, and was later changed to Setsuzo FURUKAWA.)
安政5年（1858年）、江戸の中津藩邸に開かれていた蘭学塾の講師となるために吉川正雄（当時の名は岡本周吉、後に古川節蔵）を伴い江戸へ出る。