- Title: Okahachiro
Ujisuke was the eldest son of Ogasawara Mimasaka no Kami Ujikiyo (1529-1569) and inherited his domains in 1569. He initially served the Tokugawa and fought at the Battle of Anegawa (1570). in 1574 he was besieged in Takatenjin castle by Takeda Katsuyori, and to the shock of his family (serving elsewhere in the Tokugawa domain) he surrendered, afterwards being given a fief at Omosu in Suruga province. After the fall of the Takeda he fled to the Hôjô domain. He was assassinated after the fall of the Hôjô in 1590, and went down in family history as a disgrace.