Ogyu Watar was born in 1839. He was the eldest son of Noritoshi Matsudaira.
Ogyu Watar succeeded to his 16,000-koku fief. After the Meiji Restoration (1868), he changed his family name to Ogyii and served in the Imperial Government. After serving as a Senate member and President of the Decoration Bureau, he became a member of the Privy Council (1909).
Most of the types of Japanese decorations were designed by him. After he became president of the Decoration Bureau, he avoided connections with high-ranking persons and even eschewed Court and other parties so that he might be impartial in his duties.