The story will begin with the "organization" waking up within the darkness without a memory of before. the only ones who will remember the events of kh2 will be sora, riku, kairi, and mickey. The "revived" ansem, aka xehanorts heartless, will be seeking out the organization out to become whole once more.
Thats basically the plot of the main baddies. the goodies should be self explanitory. stop the baddies. xD
Organization members, though, can either be good or bad in this story.
I will either be playing riku, demyx, saix, or xigbar.