The class was also referred to by internal Japanese documents as the "A-class" coastal defense vessel (甲型海防艦, Kō-gata kaibōkan).

The Shimushu-class kaibōkan, as with the Chidori class torpedo boat, was a consequence of the 1930 London Naval Treaty, which placed limitations on the total destroyer tonnage the Imperial Japanese Navy was permitted.

[1] Due to the low priority of the project, the design of the Shimushu-class was subcontracted out to a private firm, Mitsubishi Heavy Industries.

The secondary role of the new class was to be minesweeping, and convoy escort was considered a minor third priority.

[1] However, the design developed by Mitsubishi was more complex than the Imperial Japanese Navy had anticipated, with a double-curved bow and a forecastle deck which improved seaworthiness in the rough northern seas.

The ships had two diesel engines, each driving one propeller shaft, which were rated at a total of 4,200 brake horsepower (3,100 kW) for a speed of 19.7 knots (36.5 km/h; 22.7 mph).