This letter suggests that Korin did not consider his art work a family business, and because there was no established business to leave to his son, he had decided to send Juichiro to another merchant family to be adopted.
このことから、光琳が画業を「家業」と見なしておらず、しっかりした家業がないため、息子の寿市郎を他家へ養子に出す決心をしたことがわかる。