It was developed by tri-Ace (Star Ocean, Valkyrie Profile) and published by Sega. Definitely underrated; I had it backlogged for 3 years because it simply failed to grasp my interest right off the bat at the time I bought it, but now that I'm focusing more on backlog cleanup prior to PS4 launch, I gave it a second chance and really, really liked it! How about you, what are you playing these days, Furuba-chan?
The battle system takes a few hours to get used to, but once you get the hang of it (and if you abuse the 6x Exp trick at the Arena) it's really not too bad.