With her world overtaken by Darkness, a young Minnesota girl finds herself landing in a lake in prairie on a world far from home. There, she is found by a being of nothingness, who assigns a woman of even purer Darkness than the Heartless to take her on a journey to restore the girl's world before the resurgence of the Heartless comes to pass.

Riku's been acting increasingly aggressive lately, so Sora and King Mickey decide to enter his mind to investigate. There, they find themselves in a strange new world unlike any they've seen before, and are tasked with rescuing and teaming up with Riku's various Emotions to destroy the darkness controlling Riku once and for all.

After giving up her existence to save Roxas, Xion finds herself in a strange but broken place where Sora's memories are stored like a library and five odd and emotional beings are working tirelessly to fix him. As core memories mysteriously appear wherever she is, Xion thinks back on her situation and wonders if she's really ready to stop existing, even if it comes at a dear cost.

The first week of being a Nobody is always the toughest but nobody has it harder than the emotions themselves. Joy didn't have a leading role in Ienzo's life and now she will never have a role at all in Zexion's. But she's ever the optimist and she's going to make him smile, with or without a heart.