德川家定
The former "daimyō" of Mito Domain, Mito Nariaki was regarded as one of the foremost experts on military matters within the Japanese government, and was a strong proponent of rangaku studies to acquire military technology from the European powers. The domain had already experiments with small, western-based designs in the 1840s in secret. In December 1853, the domain received official authority from Shōgun Tokugawa Iesada to construct a large warship, based on designs and reverse-engineering from textbooks and reference materials acquired from the Dutch. The new vessel was launched in 1855 with some difficulty, and was named and commissioned into service in June 1856.