In 1939, the Japanese Army Air Force Examination Department began the concept development of what became the Special tank No.

[3][4] In the fall of 1943, the Imperial Japanese Army's Teishin Shudan formed the 1st Glider Tank Troop.

Before the 1st Glider Troop was established, the only heavy support available to Japan's airborne infantry was provided by the Kokusai Ku-8.

A small tank that could be towed on a glider by a powered aircraft and then released and glide down to the battlefield along with paratroopers.

[1] The glider developed for the Ku-Ro was the Maeda Ku-6 a 700 kg twin boom craft, which was specially designed to fit the tank.

The tracks of the tank were unable to match Ki-21's take-off and landing speeds and since taking-off and landing would cause a great amount of damage from friction to the tracks, a pair of detachable skis were made part of the glider.

[1] The cancellation was caused by a combination of technical problems, related to the poor maneuverability of the glider and stress on the tank, and the changing nature of the war for Japan.