Hasegawa produced a limited series of the Kyufo Prototype containing a different engine cowling, two contra-rotating two blade propellers and a new canopy. However, some other differences to the Kyofu Model 11 have to be corrected: the more narrow main float strut, the steeper leading edge of the vertical tail plane and removal of the wing armament.

Source: Military Aircraft Special Issue: Imerial Japanese Navy Aircraft of the Pacific ar Vol. II March 97, Delta Pub., Tokyo.

The model shows the first prototype during the flight trials at Osaka bay in May. In the photograph of the original the antenna mast has been removed.