Shōhei Maru (昇平丸) was a sailing frigate constructed on orders of the Tokugawa shogunate of Bakumatsu period Japan by Satsuma Domain in response to the Perry Expedition and increasing incursions of foreign warships into Japanese territorial waters.

[2] Following the July 1853 visit of Commodore Perry, an intense debate erupted within the Japanese government on how to handle the unprecedented threat to the nation’s capital, and the only universal consensus was that steps be taken immediately to bolster Japan’s coastal defenses.

Citing the need to protect Japanese sovereignty over the Ryukyu Islands, Satsuma daimyō Shimazu Nariakira successfully petitioned the Tokugawa shogunate to lift the prohibition on the construction of large ocean-going vessels in December 1852.

A shipyard was constructed on Sakurajima and the new vessel was launched in May 1853 even before the July 1853 visit of Commodore Perry, and his fleet of "Black Ships" to Edo Bay.

The new ship was apparently built using manuals obtained from the Netherlands via the trading outpost of Dejima, and occasional observations of foreign vessels roaming the waters off Japan.