Japan had already invested R&D in skin radar, Plasma actuator technology, Swarm drone technology.Honestly, we have only begun to scratch the surface of fifth gen capabilities, we should pursue incremental technologies that are known quantities and do-able, the first rule of goal setting in programs is that it must be practical, and "attainable", no need to get ahead of the curve and spend money we don't have, pursuing something that "might work", and really all this talk of "blah, ba blah, blah, blah!" pie in the sky by and by?
Not saying there won't be a break-through technology developed tomorrow, but for now lets stick to real life and pursue the nearly endless possibilities that the fifth gen aircraft offer us today and for the foreseeable future!
The Japanese commercial sector is investing in HMD technology and material science.
Basically the 5th generation technology was about stealth, high angle of attack and super cruise which which all boils down to usage of advanced ceramic material.The 6th generation is not trying to enhance those areas.
The 5th generation will be foundation of the 6th generation plane which will gear more into electronics and communication technology like skin radar and swarm drones so nothing is going to be lost from the 5th generation and will be a natural evolution.