I don't read Japanese either. Nevertheless, you can pick it up fairly easily, you just can't get too deep into the systems.
Not being able to read any of the ability names means I'm kind of out of luck for picking which abilities to train or even how to swap them out.
But Ace is easy to pick up, and the controls are really intuitive. Most of the systems will even explain themselves if you stick with it long enough.
Controls:
L Button - Brings up the quick menu (let's me switch characters with <- and ->, but that's all I know about this menu)
R Button - Centers camera behind player, or Locks on to a target (huge help, since it also lets you see Counter indicators)
Analog - Movement
D Pad - Camera (useless)
Triangle - Primary Attack
Circle - Special Ability (Unique to character, utilizes a gauge which charges as you attack)
Square - Magic
X - Block/Dodge
The gameplay itself is really fun. Like Kingdom Hearts but with no jump ability. Each character plays pretty differently, with different attacks and abilities. And you can at least tell where to go on a map without needing to understand the language.
As I said, I got this in anticipation of the fan translation (which I've plugged twice in the Type-0 forum but nobody seems to be interested in), which is looking really good, and the video previews of their translation can give you an overview of the setup, enough that you'll be able to tell what's going on as you play through (most of it, there is one set of scenes that are a little disjointed involving members of the Milites military, but since they don't interact with anyone I know, they could be doing anything).
Honestly, I cannot recommend this game enough. It really is some of the most fun I've had with a Square title in a long time. It's pulled a lot of good elements from all over their works (I can see influence from VIII, VII, Tactics [the original], KH, and plenty of others), and combines them into an absolute gem. Check out the promo vids on the translation page, and then try to get at least the Japanese demo. This game is great.