Also known as: Naomasa (直昌), possibly Tooyama Naotsugu (遠山直次)

Tooyama Yasuhide was a vassal of the Houjou Clan, son of Tooyama Yasumitsu. His family traditionally served the Houjou in the capacity of musicians, but in 1560 became the magistrate of the Miura District in Sagami for Houjou Ujiyasu. He along with his uncle Tooyama Tsunakage held the front line against the Satomi Clan. After Oota Ujisuke's death in 1567, Yasuhide became master of Iwatsuki Castle. He was part of the Houjou force that met Takeda Shingen's invasion of Suruga. He was sent along with his father as a Houjou representative to the peace negotiations with the Uesugi in the Echigo-Sagami Alliance. He later became a close advisor to Houjou Ujimasa and was responsible for contact with the Uesugi Clan.

Opinions differ on how he died. One view hold that he committed suicide with his father and Uesugi Kagetora in the Otate no Ran, while another says that he served Nakamura Kazuuji after the fall of Odawara Castle.