Comparing: O-I Experimental vs. BDR G1 B

Development of this superheavy tank was initiated by Colonel Iwakuro from the Army Ministry of Japan. The project was carried out by the Mitsubishi company, therefore the vehicle became known as the Mi-To. In the army, the tank was designated the O-I. Details of the project are largely unknown.

The project of a new vehicle was suggested by engineers of the Baudet-Donon-Rousell company in June 1938. However, the design was never developed.