His connections with the Imperial Family of Japan were strong. His second daughter became the wife of Prince Nashimoto Morimasa. This marriage produced for Naohiro two granddaughters, the elder of whom named Masako who became known as Bangja, consort to the heir to the Korean Yi dynasty. Naohiro's fourth daughter named Nobuko married Tsuneo Matsudaira and one of their daughters became Princess Chichibu. She also gave birth to Ichirō Matsudaira, who married Toyoko Tokugawa, Iemasa Tokugawa's daughter, and gave birth to Tsunenari Tokugawa, the eighteenth head of the Tokugawa clan. Naoharu died in 1921, and his grave is at the Aoyama Cemetery in Tokyo.
