The Mitsubishi ATD-X Shinshin is a Japanese research aircraft being developed for the Ministry of Defense Technical Research and Development Institute (TRDI), that is still in development. ATD-X is the acronym for Advanced Technology Demonstrator-X.
The reason for development of the ATD-X is that Japan was searching for a replacement for the F-15J Eagle. At first Japan wanted, like the United States, to replace the F-15 Eagle with the F-22 Raptor. But buying the F-22 Raptor was not possible for Japan, the reason being was a veto by the United States congress that forbode selling high tech weapons even before Japan had tried to buy the F-22 Raptor. Even after an under license built F-22J Raptor was forbidden, Japan began developing its own Air-Superiorty fighter. Because Japan, has no real experience with combat aviation, and the Japanese projects of the last few years were all finished with the help of the United States, Japan called Lockheed Martin for help. Lockheed Martin was chosen because of positive experience with the development of the Mitsubishi F-2.
Development of the ATD-X is currently at an early stage. However, ground testing with a first mock up was absolved in France. Even with its planned finished prototype by 2014 and first flight in 2016, whether or not the project will be fully realised is questionable, it is believed the aircraft is only being developed to gain experience with stealth technology, a service entry is not being planned since then.
The ATD-X is expected to have lots of constructive similarities with the F-22. Unlike on the F-22 3D TVC is planned but this will lower the stealth capability of the aircraft.