Симодский трактат
The need for the ship arose when Putyatin's fleet was damaged in a tsunami, following the powerful Ansei-Tōkai earthquake of 23 December 1854. The flagship "Diana" sank on its way from Shimoda to Heda as it was sailing there for repairs. Following the signature of the Treaty of Shimoda with the Russians, the Japanese government decided to help the Russians return to their country by building a western-style ship.