徳川家治
was the 7th Niwa "daimyō" of Nihonmatsu Domain, and 8th hereditary chieftain of the Niwa clan. His courtesy title was "Saikyō-no-daifu", and his Court rank was Junior Fourth Rank, Lower Grade. He was the eldest son of Niwa Takayasu by a concubine and became "daimyō" in 1766 on the death of his father. He was received in formal audience by Shōgun Tokugawa Ieharu the same year. He was married to a daughter of Date Muratoki of Uwajima Domain. During his tenure, the domain suffered from the effects of the Great Tenmei famine. He died in 1796 and his grave is at the temple of Dairin-ji in Nihonmatsu.