Dogyu, fulfilled with his deepest desire, went to Nagasaki in 1686 and had an opportunity to learn 'Caspar-style red-haired surgery' which had been spread by Schamberger CASPAR, a medical officer to the captain of the Dutch trading house.
貞享3年（1686年）、念願かなった道牛は長崎に赴き、オランダ商館付きの医官カスパル・スハンベルゲルが広めた、「カスパル流紅毛外科」を学ぶ機会を得る。