The Kawasaki Ki-61 Hien was a WWII Japanese fighter powered by the Ha-40 engine - a license-produced version of a Daimler-Benz power plant. On account of its liquid cooled engine (it was the only Japanese fighter in the Pacific fighting to have one), the Hien was apparently mistaken for a German aircraft and then for an Italian bird, and was given the reporting nickname "Tony." It saw combat action from early 1943 and proved a competitive aircraft with its top speed of 580km/h, used in the desperate Japanese defense of the Solomon Islands and even as an interceptor when U.S. B-29s got in range to bomb the Japanese home islands toward the end of WWII.