Since Senchiyomaru, the oldest son of Tsunamura DATE who was the fourth lord of domain, died young, Yoshimura became an adopted heir and took over as the head of the family in 1703 at the same time as the retirement of Tsunamura, his foster father.
第4代藩主・伊達綱村の長男・扇千代丸が早世したために養嗣子となり、元禄16年（1703年）、養父・綱村の隠居にともない家督を継いだ。