Chief retainer of the Sendai Clan (Miyagi Prefecture). When lord of the clan, Tsunamune Date, retired because of illness, his heir, Kamechiyo-Maru (Tsunamura) was still a child and Munekatsu Date, a relative, abused his power. Another relative, Muneshige, reported this to the Shogunate. When the Shogunate was about to hold a trial of the case (March, 1671) Kai Harada, a supporter of Munekatsu, attacked and killed Munekatsu. Geki immediately killed Kai but was slain himself.
The trouble, called Date Sodo (Date House Affair), became famous in stories and plays extolling the loyalty of Geki.