the Mitsubishi ATD-X F-3 Shinshin (Shin Shin is an unofficial name). The aircraft will incorporate three-paddle 3-axis thrust-vectoring* (the F-22 has only 2-axis pitch vectoring), a fly-by-optics (not wire) flight control system, active phased array radar**, ECM, ESM, and a feature called ‘Self Repairing Flight Control Capability’ which will allow the aircraft to automatically detect failures or damage in its flight control surfaces, and using the remaining control surfaces, calibrate accordingly to retain controlled flight.Japan is also developing an axis-symmetric thrust vectoring nozzle.
J-20 first flight 11 January 2011 is still years from entering service. Not to mention China has significantly better aviation technology than Japan does with J-10B. Even if F-3 first flight can be done by 2020, it won't do any good.