Other work flagged for the i3 Fighter might be enticingly dangled under the Pentagon's nose, though. The Technical Research and Development Institute and industry are working on skin sensors, directed-energy weapons and advanced avionics.

Arguing that neighboring countries—meaning China, South Korea and Russia—will have stealth fighters and longer-range missiles in the 2020s, the ministry is asking for ¥1.6 billion in fiscal 2013-16 to study integration of antennas into the skin of an aircraft, thereby helping to control radar reflections. The antennas would be those for electronic support measures, which listen to enemy transmissions, and electronic countermeasures (ECM), which jam and confuse them.

The ministry also wants to push ahead Japanese ECM technology, to preserve national independence in that area that was developed in building a system for the F-15. The ECM work must be part of what the ministry calls an “all-around surveillance and jamming system.” Japan is also looking for “reflection suppression” technology, apparently distinct from stealth shaping and materials. Details are unavailable. Results of this electro-magnetic work are to be assessed in 2019.

From fiscal 2010 the institute ran a ¥2.5 billion study on “internal weapons aerodynamics,” apparently an investigation into releasing bombs and missiles from bays, and now it wants ¥3.8 billion for further work, including a test rig.