22 years after the events of the original Kingdom Hearts, history is begining to repeat itself, just in its own way. One of Maleficent and Xehanort's Heartless' (let's call him "Reigen", Japanese for heartless, until further notice) two children, Aquaria (namely me) manages to become dictator of Hollow Bastion. Aquaria also happens to be Daddy's favorite.
The other daughter, Darkli, though she is 8 years older than Aquaria AND is half-Heartless, is scared to death of her; their parents tought Aquaria how to manipulate the dark while Darkli was left to discover on her own. From this point on, she was determined to stop her little sister's reign at any cost, but to no avail.
On to Destiny Islands... Sora and Kairi have 3 children: Jeff and Rae are the 15-year-old twins. The youngest, Kara, is only 4 years old and is mentally unable to communicate anywhere near as well as her peers (autistic. yeah this one's a character dedication).
Jeff and Rae's two best friends are named Dan and Jenna (whom everyone just calls "Polar" because of her albino hair). Dan is Tidus and Yuna's child.
Neither Jeff, Rae, or Dan seem to know where Polar came from; Heck, neither does she. The adults may know something, but won't tell any of them what they know about where they know.
After Reigen tries to sabotage Destiny Islands and capture the Keyblader of Light, Rae, Jeff, Dan and Polar are left without a home and flee to Traverse Town, where they meet their "long-lost" aunt and uncle. And a deadly assassin who wants nothing more than revenge.