Kaimon (海門, Sea Gate)[1] was a sail-and-steam corvette of the early Imperial Japanese Navy.

Kaimon was a three-masted bark-rigged sloop-of-war with a coal-fired double expansion reciprocating steam engine with four boilers driving a single screw.

The design of Kaimon was almost identical to the corvette Tenryū, completed a year later at the Yokosuka Naval Arsenal.

Both ships were designed by French foreign advisors to the early Meiji government in the employ of the Yokosuka Naval Arsenal.

During the Russo-Japanese War, Kaimon was assigned to patrol duties between the Korean Peninsula and Tsushima Strait.