Pfft!
Dragged out so long, couldn't bring proper closure to the story... go figure.
That's what tends to happen with stories like these - they're no One Piece, Naruto, or Detective Conan...
So, Yuuna lives on by possessing Kogarashi for life... mmkay. And everyone else is left hanging, blah, blah, blah.
Well, at least it got an ending - good riddance.