Osada Kagemune (長田景致)
He participated in the plan led by his father, Tadamune, to assassinate MINAMOTO no Yoshitomo; moreover, he also killed Masakiyo KAMATA, Yoshitomo's closest Vassal and Kagemune's Gikyodai (relationship associated with each other as brother), during the assassination. He always appeared together with his father in "Tale of Heiji," beside the scene of assassination and they worked well together.
It is said that both Kagemune and Tadamune were also executed together by the order of MINAMOTO no Yoritomo, a child of Yoshitomo.
Furthermore, it is also said that his descendants escaped to Mikawa Province and named themselves as NAGAI, or escaped to Kai Province and retained the family name.