In 1736, he became Sweet Potato Goyo-gakari (a general affairs official) and in 1739, he became the superior purveyor of books writings/letters, Konyo left the sweet potato cultivation and became a shogun's retainer.
元文元年（1736年）には薩摩芋御用掛、元文4年（1739年）には御書物御用達となり、昆陽は薩摩芋栽培から離れて幕臣になる。