There were many of Rangakusha (a person who studied Western sciences by means of the Dutch language) and doctors, who visited Kogyu (Yoshio)'s residence or leaned at Seishukan, and most of the leading Rangakusha at the time, including Konyo AOKI, Genjo NORO, Gentaku OTSUKI, Baien MIURA, Gennai HIRAGA, Shihei HAYASHI, and Kokan SHIBA, had contact with him and gained much knowledge from him.
吉雄邸を訪れ、あるいは成秀館に学んだ蘭学者・医師は数多く、青木昆陽・野呂元丈・大槻玄沢・三浦梅園・平賀源内・林子平・司馬江漢など当時一流の蘭学者は軒並み耕牛と交わり、多くの知識を学んでいる。