Shigekage served Date Terumune and Masamune and held Kaneyama castle in Mutsu province. He served Masamune on campaign against the Ôsaki family and in 1594 accompanied Masamune to a personal audience with Toyotomi Hideyoshi. At this time he changed his name to Yamaoka Shima. He went on to serve in the Osaka Castle Campaigns.
- Initial text from Sengoku Biographical Dictionary (Samurai-Archives.com) FWSeal & CEWest, 2005