Bücker Bü 131 Jungmann Kyūshū K9W1 Momiji

The Imperial Japanese Navy was the first to bring the Jungmann to Japan. According to History of War, in 1938 a demonstration Bü 131B flew before naval officers, who bought that aircraft and in 1939 ordered 20 more for evaluation as the Navy Experimental Type Bu Trainer. Convinced, the Navy acquired a production licence. Early attempts to build the aircraft at Hitachi and Watanabe failed, and it was not until August 1942 that Watanabe got the series under way as the K9W1; the company was renamed Kyūshū Hikōki in 1943, which is why the aircraft appears under both names. The official designation was Navy Type 2 Primary Trainer Model 11, the Japanese name Momiji ("maple") and the Allied code name "Cypress".

The K9W1 was powered by the 110 hp Hitachi GK4A Hatsukaze 11, a Japanese version of the Hirth HM 504. History of War, the English and German Wikipedias and the Air Britain Digest agree on 339 aircraft built; the Air Britain Digest breaks them down into 278 by Watanabe/Kyūshū and 61 by Hitachi. The German Wikipedia places the start of production in 1943.

The Momiji's success at the Navy's schools caught the Army's attention, which, rather than share Kyūshū's line, ordered its own version from Kokusai: the far more numerous Ki-86, with 1,037 aircraft. Together they made Japan the largest foreign producer of the Jungmann.