This book is perfect for fans who want to play as their favorite Anime characters -or similar ones- in Pathfinder 1E. Some classes and races are Sci-Fi rather than Fantasy but they could be used in a Numeria or Starfinder campaign. And of course a GM can just make his own setting including a Final Fantasy-esque one where all options apply! The point-based character creation system gives a player the option to make unique characters as well.
The art is also pretty good, some of the best I've seen in an Anime RPG. My only caveat is that there are several small editing errors, but nothing that an Errata cannot cover and I'm sure they will be fixed in a later edition.
As for expansions I'd like to see: Foes, a Setting, and a specific Campaign - this is perfect for Issekai.