Date clan
Narikuni was the son of Date Munemitsu of the Tome-Date clan, a subsidiary branch of the main Date clan, and was the grandson of Date Yoshimura, the 5th "daimyō" of Sendai. His childhood name was Kōgorō (幸五郎) later Tosaburō (藤三郎) and become Sojirō (総次郎).