Mitsubishi G1M1/Ka-9

The Mitsubishi Ka-9 was originally designed to perform aerial surveillance over the Pacific. It was the first prototype in the series of aircraft that would later be known as the Mitsubishi G3M 'Nell'. The Imperial Japanese Navy's (IJN) first ambitious attempt to produce a long range bomber was part of the Experimental 7-shi programme of 1932, which was hoped for that programme to produce a new generation of Japanese naval aircraft. However, the only successful to come out from it was the Kawanishi E7K reconnaissance seaplane, while the only land-based bomber to emerge from the programme was the Hiro G2H, which flew for the first time in 1933 which, although it had the required range, it lacked performance in many other factors like speed and, eventually only eight of them would be built in 1935.
In 1933 the head of the technical development at the Naval Aircraft Establishment was the Rear-Admiral Isoroku Yamamoto, who was convinced that the IJN needed a long-range land-based bomber to be used as a defensive weapon from bases on the scattered islands of the Japanese Empire in the Pacific Ocean. It was clear that the G2H wasn't that aircraft, so Yamamoto gave Mitsubishi in early 1933 a non-competitive contract to produce a long-range, high-speed multi-engined monoplane. No bomb load or performance figures were issued, giving Mitsubishi free reign.
Mitsubishi was chosen because in the late 1920s it had developed strong bonds with Junkers. In fact, in 1928 they had purchased a number of licences for Junkers' aircraft designs and, by the start of 1933, they had designed the Mitsubishi Ki-1, Ki-2 and Ki-20 bombers for the Imperial Japanese Army Air Force. A number of Japanese engineers, among them Sueo Honjo (who designed the Ka-9), had also received training from Junkers.
Sueo Honjo was the main chief engineer in charge of the "Navy's Project 435" or, "Experimental 8-shi reconnaissance plane". Internally at Mitsubishi it was known simply as "Ka-9".
The Ka-9 was completed on 18th April 1935 and was a twin-engined monoplane powered by two Hiro Type 91 engines which gave 650 hp of power each. It had a slim streamlined fuselage, twin vertical tails and rudders, and Junkers' double wings. On this design, a second, much smaller airfoil was mounted on the back of the main wing. The gap between the two wings increased lift, specially when the aircraft flying at a step angle, either when climbing or landing, at the expense of increased drag. It was also the first Japanese military aircraft to have retractable landing gear.
Yamamoto was among the first people to test the aircraft and was impressed by its performance. Honjo had produced an aircraft with a range of 3265 nautical milles (6047 km), better than any contemporary military aircraft. The Ka-9 was given the short designation of G1M1 by the IJN making it the first entry in a new land-based bomber sequence.
Mitsubishi were therefore rewarded with the Navy Project 79 for the Navy Experimental 9-shi land based attack plane, which would eventually emerge as the Ka-15 and accepted into IJN's service as the G3M.
The sole G1M1 was used as a testbed for Mitsubishi's 14-cylinder Shinten twin-row air cooled radial engines, which could yield the impressive amount (for the time) of 920 hp but only could increase aircraft's speed by 15 mph (24.1 km/h) and were very unreliable.

Sources:
1. http://www.historyofwar.org/articles/weapons_mitsubishi_G1M1.html
2. https://elpoderdelasgalaxias.wordpress.com/2013/07/01/mitsubishi-ka-9-name-it/
3. https://www.secretprojects.co.uk/threads/mitsubishi-ka-9-8-shi-special-reconnaissance-plane-g1m1.23519/
4. https://www.valka.cz/Micubisi-G1M1-t64820
5. https://en.wikipedia.org/wiki/Mitsubishi_G1M