Not on its own at least. Much of the F-2s technologies were from the United States, not to mention the components. For a fifth generation fighter like the X-2, I highly doubt the US would be willing to do many technology transfers for sensitivity issues, especially on the stealth side. I really doubt the X-2 will be successful unless the US and Japan reach an agreement on these issues ... far more likely the US might develop a F-35 variant to suit Japanese needs imo.
Which they already rejected? Thus its future fighter program dubbed F-3. X-2 is only a tech demonstrator.
Yes, Japan got lots of help developing the F-2 but the core technologies were developed themselves as well. The AESA radar which was very very new back then, composite uni-structure wing and so on. The US refused to transfer the tech related to flight controls so they just went on and developed 4 channel FBW based on their experience from developing the F-1 as well.
Actually, they did get engine tech from the US but it was in exchange for the tech transfer of aforementioned composite wing fabrication technology to the US.
Nowadays they've already deployed FBL controlled aircraft and newer iterations of their AESA radar. The R&D of core avionics hasn't stopped ever since F-2 development.
You're opinions about Japan being incapable of developing 5th gen fighter are too far-fetched. It's actually even funny considering F-3 is going to be deployed almost 30 years after F-22.