Keys to the Kingdom Hearts

I know next to little with Kingdom Hearts: As far as I'm concerned, it's Disney meets SqueeEnix with legions upon legions of scary fangirls chomping at the bit for some mansex. As such, Kingdom Hearts goes no further with me than acknowledgment of it's existence.

Still, I have to admit that I was interested to learn that with the latest incarnation of Kingdom Hearts, a female character was been included in the playable party: Aqua.
Again, I know little of Kingdom Hearts but I have very good ideas as to what makes an compelling gaming heroine. So having a courageous heroine who can rough 'n tumble with the best of them is welcome in my book. She looks cool too.

But then again, this is Kingdom Hearts we're taking about, where the entire male cast already look girly enough as it is. So I assume there is a reason to Aqua's existence....