The was a class of auxiliary escort carriers built for the Imperial Japanese Navy (IJN) during World War II. They were converted from Type 1TL tankers. It is also called the class in some western sources.
Although four conversions were reportedly considered, only two ships were launched, with just one being completed, and neither entered active service before being destroyed.
The concept of the class was similar to the British merchant aircraft carrier. The class consisted of two oil tankers of that were modified by the Navy to provide minimal anti-submarine air cover for convoys going from Southeast Asia to the Japanese homeland. The conversion consisted of fitting a full-length flight deck, a small hangar, and a single elevator. An island and catapults were not installed. The only other change was the rerouting of the boiler uptakes to the aft starboard side where they discharged in a typical downward-facing funnel.
The ships had a length of overall and between perpendiculars. They had a beam of at the waterline and a mean draft of . They displaced at standard load.
The Shimane Maru-class ships were fitted with a single geared steam turbine set with a total of . It drove one propeller shaft using steam provided by two boilers. The ships had a designed speed of and a range of at .
The flight deck was long and had a maximum width of . The hangar, built on top of the well deck, was served by a single elevator from the flight deck. It had a capacity of a dozen aircraft.