In 1686, at the age of 31, Sorai was recruited by Yoshiyasu YANAGISAWA, who was a close associate of the fifth shogun Tsunayoshi TOKUGAWA and Edo bakufu Sobayonin (lord chamberlain), and he served Yoshiyasu on the salary of 15 man fuchi (the equivalent of an annual ten-man rice stipend).
元禄9年（1696年）、徂徠31歳のとき、5代将軍・徳川綱吉側近で江戸幕府側用人の柳沢吉保に抜擢され、15人扶持を支給されて彼に仕えた。