I will not give any spoilers.
The story is a nice little tale of a young girl who lost her brother, and now is on a quest to destroy the world. She has a glowing orb, which she thinks is the "destruct code." Along the way she picks up a goofy young cook, and a little bear. And so their adventure goes.
IF you want to watch this show, you had better like semi slower pacing and episodic structure. Each episode is usually self contained, either wrapping up in one episode or a two parter. The main story isn't really important until the final few episodes, like most shows are. The main point of this show is character development. We meet people from the characters past, and find out plenty of interesting little facts about them. This can be quite boring. So unless you really like the characters, this won't be that fun for you. But besides that, it is a pretty common storyline, with not much to make it stick out in the growing crowds of anime.
Watch a couple of episodes and see if you like it. do a trial run.