The J2M was designed by Jiro Horikoshi, creator of the Mitsubishi A6M "Zero". It was strictly a local-defense interceptor intended to counter the threat of high-altitude bomber raids, and thus relied on speed, climb performance, and armament at the expense of maneuverability. The J2M was a sleek but stubby craft with its over-sized Mitsubishi Kasei engine buried behind a long cowling, cooled by an intake fan and connected to the propeller with a long extension shaft. Pilot visibility was poor.