Moshun Maru (孟春丸, Vernal Equinox) was a three-masted composite-hulled sailing ship of the Bakumatsu and early Meiji periods, with an auxiliary steam engine.

Initially assigned to be an armed cargo vessel, she transported supplies and troops from Nagasaki to Osaka, and later the Edo in support of the Satchō Alliance in the Boshin War of the Meiji Restoration.

In March 1869, she was assigned to the expedition against the last remnants of the pro-Tokugawa shogunate forces in Hokkaidō, where they had formed the Republic of Ezo.

While at Miyako Bay, the expedition suffered a surprise attack by the Tokugawa naval ship Kaiten.

She was demobilized and transferred from the Imperial Japanese Navy to the Ministry of Communications on October 8, 1887 to serve as a training vessel for commercial sailors.