The Kawasaki Ki-61 was a single-engine fighter aircraft developed by the Japanese company Kawasaki Heavy Industries during World War II. The aircraft was also known by its Allied reporting name “Tony”.

The Ki-61 was designed to meet the Japanese army’s requirements for a high-performance fighter to replace the earlier Ki-43 Hayabusa. The first prototype flew in December 1941, and the Ki-61 entered service with the Japanese army in 1943.

The Ki-61 was a low-wing monoplane with a liquid-cooled inline engine and retractable landing gear. It was armed with two 20mm cannon and two 7.7mm machine guns mounted in the wings. Later variants of the Ki-61 were equipped with additional guns and rockets for ground attack missions.

The Ki-61 was considered one of the best Japanese fighters of the war, with excellent performance and maneuverability. It saw combat in the Pacific, China, and Southeast Asia, and was used by some of Japan’s top fighter aces. However, it was also plagued by engine reliability problems and suffered from a lack of spare parts due to Japan’s dwindling industrial resources.

Despite these issues, the Ki-61 remained in service until the end of the war, and was used in several major campaigns, including the defense of the Philippines and the defense of Japan. It was also exported to other countries, including Thailand and Manchukuo.