Moritoshi Taira was a Kebiishi (Police Commander). In the war of Heiji Era accompanied Shigemori Taira and defended Rokuhara in Kyoto against Yoshihira Minamoto. Defeated Yukiie Minamoto at Sunomata, Mino Province (Gifu Prefecture) (1181). Defended Kyoto against Yoshinaka Kiso, headquarters of the forces of Koremori Taira.
Fought Kanehira Imai, a general of Kiso, in Etchu Province (Toyama Prefecture). Was killed in the Battle of Ichinotani.