He 112B in Japanese Service
In 1937 the Teikoku Nihon Kaigun (Japanese Imperial Navy) found itself at a disadvantage in combat over the Chinese mainland. The fact that Navy aircraft were fighting over the mainland might seem odd, but interservice rivalry in Japan went beyond the occasional bar brawl and both services fielded complete air forces with their own types of planes.
At the time the Navy air services were small and equipped mostly with older biplanes. Meanwhile the Soviets were supplying the Chinese air forces with the I-15bis and I-16 fighters. Although the new A5M "Claude" was largely similar to the I-16, they were just starting to enter service and available in small numbers only. The Navy was concerned about the lack of fighters and went looking for new designs that could be purchased off the shelf to bring the squadrons to strength quickly. At the time the majority of modern design work was taking place in Europe, and with England no longer on friendly terms they turned to Germany for a new fighter.
In late 1937 a delegation visited Marienehe and saw V9 in action. They were impressed with what they saw and placed an order for thirty of the B series planes, with an option for 100 more. They even purchased one of the older designs to take back with them immediately (according to the primary source below, this was the V5). Upon arriving in Japan the planes were named A7He1, the A7 refers to the 7th navy fighter design (the Zero was 6th), and the He1 means it's the first version of this particular design, and built by Heinkel.
In testing the He 112B proved superior to the A5M2 in many ways, notably in speed where the 112 could easily outrun the A5M to the tune of 65km/h. Yet the test pilots rejected the plane out of hand because the A5M was more maneuverable. Maneuverability was considered to be the single most important factor for any fighter, everything and anything was sacrificed to improve it. It could be said that the Japanese were still fighting WWI in the air, and the focus on maneuverability would later prove to be the downfall of their air forces.
In the end the plane was rejected and the option for the additional 100 was canceled. The thirty already purchased were delivered over a period in 1937 and '38, drawn from a number of production runs. Upon arriving in Japan they were used for training duties, but the V11 with it's DB600Aa was used for testing. As it turns out the A7 designation would later be assigned to the A7M, essentially an advanced Zero which also never saw combat
From
http://www.csd.uwo.ca/~pettypi/elevo...her/he112.html