A great game, but without some knowledge of Japanese, you will struggle.
Its not that the game is in anyway hard, because it really isnt, the battling is easy to pickup and play. It is when you get into the adventure mode, and have to start creating your own teams that the difficulty begins.
You have to make decks or Komas out of various fighters, allies and helpers, each one taking up a different amount of spaces and made of differnet shapes, the goal is to mash as many characters and types onto your team, or Koma block.
Seeing as most of the better ally and helper komas arent available until late in the game, chances are that you will be mix-matching random Komas of characters you arent to sure what their abilities are, and hoping you can defeat the later bosses. Unlocking Komas can also be done by unlocking certain criteria, which without a good gamefaq, or understanding of Japanese can take a very long time to complete, Id estimate I only have about 60% of the komas thus far.
Other than the Koma issue, this is one of the best fighters ever created, either 2d or 3d, the action is fast and frantic, and like Super Smash Brothers, you can fight your way through the game with little practice, but it is much more fun to try and master the game.
Overall: Get the game if you liked Super Smash brothers, or like any of the Shonen Jump Characters, chances are you can use them sooner or later. Just know you may never finish the game 100% without the ability to read Japanese.