Niwa clan
was the 2nd Niwa "daimyō" of Shirakawa Domain, and 2nd hereditary chieftain of the Niwa clan. Mitsushige was the third son of Niwa Nagashige. As both of his older brothers died in childhood, he was named heir in 1628. In 1634, he was received in formal audience by Shōgun Tokugawa Iemitsu, and received a "kanji" from Iemitsu's name, becoming Niwa Mitsushige. In 1643, the Tokugawa shogunate ordered the Niwa clan to relocate to Nihonmatsu. Upon entering Nihonmatsu Castle in 1644, he immediately embarked on a program to rebuild the surrounding "jōkamachi". Mitsushige was also noted as a patron of the arts, and especially favoured the Sekishū-branch of the Japanese tea ceremony. He was also a painter, having been trained in the Kanō school, using the pseudonym Gyokuhō (玉峰). He retired from public life in 1679, turning the domain over to his eldest son Niwa Nagatsugu. He died in 1701. His courtesy title was "Saikyō-no-daifu", and his Court rank was Junior Fourth Rank, Lower Grade.