Later, Choei moved to Nagasaki for learning medical science and Western studies at the Narutakijuku founded by Philipp Franz von Siebold, where he was appointed as a school manager for his outstanding academic ability.
その後長崎に留学してフィリップ・フランツ・フォン・シーボルトの鳴滝塾で医学・蘭学を学び、その抜きん出た学力から塾頭となっている。