The Japanese aren't even mentioning anything about fixed wing STOVL - its just some speculative analysis that they are more or less light carriers and thus able to be used like the RN Invincibles if need be.What type of aircraft will they carry.
I'd be betting that the JSDF is a prime candidate for JSF-B in the near future. IMV, they are starting the inexorable change to asserting themeselves for their self defence and to be seen as more pro-active in the region.
They have been having more and more discussions with a number of regional militaries and I think its inevitable that they start to cement alliances. Although china is the best bet to contain Nth Korea - Japan knows that china is limited in what she can do - she won't depend on international politics and UN manouvering to deal with NK. I think we'll witness a progressive military build up under PM Abe - and hi-tech solutions like the JSF-B will get their attention.