The first prototype, made to be an intermediate trainer, with the Hitachi Ha-13a engine, first flew on January 7, 1935. It was found to be difficult to fly and modifications were made that when flown for the second time on January 9, 1935, it was found to be ready for Service Trials at Tokorozawa.
The second prototype was finished as an intermediate trainer shortly afterwards.
The third prototype had the Nakajima NZ engine installed and was to be the model for the primary trainer. Its center of gravity was far back and takeoffs weren't good.