I was pretty surprised when I didn't regret giving this a try.
I'm glad I took the plunge with this game, it's a very solid 2D fighter with a large character selection.
I have a few complaints though...
1) It's based on an anime that's been going down hill for quite some time.
2) The card system in the game feels gimmicky, and somewhat useless. I hardly ever find myself using a card.
3) The story feels very lacking, and uninspired.
4) It's too easy, even on Hard mode.
Even after those faults, you'll have tons of fun with this game. The character selection will keep you going, and the way that the combos flow is great. It feels a little odd on the DS, but once you get the controls down, it's really very simple.