Yen Sid puts Sora and Riku through a Mark of Mastery exam in order for them to become full-fledged Keyblade Masters and counter the coming return of Master Xehanort. As part of this trial, the two are separated from each other and sent to worlds previously destroyed by the Heartless that have since been restored, though now in a state of "deep sleep" that disconnects them from the other worlds. These worlds are plagued by Dream Eaters—creatures born from darkness that seek out the sleeping worlds' Keyholes. Sora and Riku's given task is to reawaken the sleeping worlds by unlocking the seven Keyholes they find there and then return to the realm of light, recruiting benevolent "Spirit" Dream Eaters to guide them and battle the malevolent "Nightmare" Dream Eaters, after which they will be deemed Keyblade Masters.
During the exam, Sora and Riku cross paths with their old enemies, Xemnas and "Ansem", respectively, as well as a younger incarnation of Xehanort who has traveled through time from an alternate past. Once all the sleeping worlds are restored, Sora finds himself back in The World That Never Was instead of the Realm of Light, where he learns of Organization XIII's true purpose—to serve as vessels for Master Xehanort to place pieces of his heart inside, thereby transforming them into clones of Xehanort. Sora is forced into a comatose state by the young Xehanort and his heart is swallowed by darkness, though it is protected by Ventus' suit of armor residing within him. Riku goes to rescue Sora, only to be confronted by the young Xehanort. Xehanort unveils a new Organization composed of the newly revived Master Xehanort and his twelve vessels, whom Xehanort plans to pit against seven Keyblade wielders and recreate the χ-blade. Master Xehanort tries to turn Sora into his last needed vessel, but Sora is rescued by Riku, Mickey, Donald, Goofy, and Lea—the revived human form of the original Organization's Axel—after which Xehanort and his other vessels return to their individual pasts.
Sora's body is brought back to Yen Sid's tower, where Riku enters his body and releases Sora's heart from Ventus' armor, now possessed by a Nightmare. After Sora reawakens, only Riku is declared a Keyblade Master by Yen Sid for awakening Sora. Undaunted by his failure, Sora congratulates Riku and embarks on a new journey by himself to train. The game's secret ending shows Yen Sid planning to gather seven Keyblade wielders to combat the new Organization and prevent Xehanort from bringing about another Keyblade War. To this end, Yen Sid has Riku bring his friend Kairi to him so she can be trained alongside Lea to wield the Keyblade she previously used during Kingdom Hearts II and the Keyblade he developed the ability to summon during the course of the game.
iTEM will be shippED within THREE WORKING DAYS.