A retainer of the Date clan, Kamigoriyama Morisuke is said to have built the flatland fortress of Oguni Castle in the Oguni district of Okitama, Dewa Province (present-day Oguni, Nishi-Okitama, Yamagata) during the Tenbun era (1532-1555), when Date Tanemune and Harumune controlled the district. Under Date rule of Okitama, he and the Kurota family jointly garrisoned the castle, guarding the western frontier of Date territory against Echigo. After the Date were transferred to Iwadeyama in 1591, Okitama passed to Gamo Ujisato and then to the Uesugi, whose successive deputies occupied Oguni Castle.

A steady, if little-celebrated, castellan entrusted with guarding the western border of Date territory.

The Oguni Castle he built continued to serve as the administrative base for western Okitama through changes of rule from Date to Gamo to Uesugi, functioning after 1692 as an Uesugi domain administrative office ("oyakuya").