Ive read that they are working on amphibious assault vessels,but the aircraft carrier aspect is still under discussion.My own guess is they will go in for small multi-role vessels which can deploy a handful of JSFs,in addition to helos.You will probably not see the JMSDF Having real carriers till after 2015.
What with all their IRBMs, MRBMs, and who knows, perhaps even their own export modified TU-95s, and TU-22Ms, air craft carriers might not buy them a whole lot. Furthermore, if they can establish some bases in Latin America, this would be even more true.