Mitsubishi's design, the Ka-17, given the short system designation F1M1 by the Japanese Navy, was a small all-metal biplane powered by a single Nakajima Hikari 1 radial engine rated at 820 horsepower , the same engine as used by Aichi's competing F1A. It had elliptical wings and great care had been taken to reduce drag, with the number of interplane struts and bracing wires minimised.