What is the name of the fighter plane Jiro Horikoshi designs in The Wind Rises?

The fighter plane Jiro Horikoshi designs in The Wind Rises is the Mitsubishi A6M Zero.

Horikoshi was the chief designer of the A6M, a carrier-capable fighter developed for the Imperial Japanese Navy. The aircraft entered service in 1940, corresponding to the Japanese imperial year 2600; this is why it became known as the “Zero.” Its Japanese designation was Rei-sen, meaning “zero fighter.”

The Zero became famous for its exceptional range and maneuverability, achieved partly through an extremely lightweight design. That lightness also meant it had limited armor protection and lacked self-sealing fuel tanks, making it vulnerable when air combat conditions changed during World War II.

The Wind Rises fictionalizes parts of Horikoshi’s personal life, but his role in designing the Zero is historically real. The Mitsubishi A5M was an earlier fighter associated with Horikoshi, while the Mitsubishi G4M was a bomber rather than the aircraft named in this question.