Title: Jibu Shousuke (治部少輔)
Historically: Master of Yasuda Castle. The Yasuda family had served the Nagao Clan from the time of Nagao Tamekage (late 1400s). Nagahide supported Nagao Kagetora (Uesugi Kenshin) in the coup d'etat against Nagao Harukage, so was a close aide of Kenshin from early on. He fought in many of Kenshin's wars against Takeda Shingen, Oda Nobunaga, and Houjou Ujiyasu.
Though he shared the same family name as Yasuda Kagemoto and Yasuda Akimoto, also vassals of the Uesugi Clan, he was descended from a different family.