It lacks of deep analysis and arguments from which each of the examples the author(s) bring up whether and how the new J main- and sub-cultures help promote "cool Japan", and whether and how they successfully make Japan great again in the world economic arena where Korean pop culture has dominated. I think the authors try, but not very successful, to tie a connection between the new sub cultures and the cool Japan campaign.
After finishing the book, the questions they ask earlier in the book still remain unanswered. The last chapter -- conclusion -- is even more vague with a lot of pointless arguments. Maybe I miss something between the line where the authors endlessly try to point out.