After visiting Olympus Coliseum and locking Deep Jungle in search of his friends, Sora and the others find a Gummi piece and travel back to Traverse Town to ask if someone can do something with it. Riku suddenly shows up saying he’s been looking for Sora. Sora invites him to join them and search together for Kairi, but Donals refuses. Sora and Donald start arguing until Goofy mentions that Riku disappeared. Sora figures he just left on his own and that he’ll be fine and they go in an empty house to meet with Leon. Riku watches from the outside with Maleficent telling him Sora has replaced him and that he’s better off without him.
After locking the Keyhole in Traverse Town, Sora makes his way to Agrabah. We see Jafar and Maleficent talk about the Heartless that are looking for the Keyhole and how Jafar still needs to find princess Jasmine because they need all seven princesses of heart to open the door. After fighting against Jafar with the help of Aladdin to save Jasmine, Sora is able to lock the Keyhole but they lose Jasmine. We see Hades, Maleficent and Riku around a table where Hades accuses Riku of leaving Jafar when he could’ve helped him defeat Aladdin and Sora. Riku argues back that he did his part by kidnapping Jasmine. Maleficent agrees and tells him Hook will help him get Kairi back like they had agreed.
After being swallowed by the whale Monstro, Sora runs after Pinocchio to bring him back to his father when Riku shows up and takes Pinocchio with him in the hopes that it’ll help him give Kairi her heart back. Sora finds him and manages to save Pinocchio from Riku. Without Pinocchio, Riku thinks he won’t be able to find a way to recover Kairi’s heart. Maleficent comes and tells him that gathering the seven princesses of heart will open the door to the heart of all worlds and he will surely find a way to save Kairi there. To help him gather the remaining princesses, she gives Riku the power to control the Heartless.
After the encounter with Riku, the trio found themselves in Atlantica. They successfully locked the world after defeating Ursula and saving Ariel in the process. Next stop was Halloween Town where they defeated Oogie Boogie and locked the Keyhole. In Neverland, Sora encounters Riku yet again and Riku shows him that he found Kairi. After separating Sora from his shadow, Riku sends him in a cell where Donald and Goofy already are. Sora meets Peter Pan and Tinkerbell in his cell and learns that Pan was there to save his friend Wendy. Sora and Pan help each other to find the girls. Pan manages to save Wendy, but Riku leaves with Kairi before Sora can save her. After defeating Hook, Pan brings Sora to the clock tower where Sora can lock the world.
Back in Traverse Town, Sora gets some kind of vision where he sees a young Kairi in a castle; and so they travel to Hollow Bastion. There, we see Riku talking to Beast, asking him how he got to Hollow Bastion. Beast tells him that Belle was taken from him when their world fell into darkness and he vowed he would find her no matter the cost and he found himself in Hollow Bastion. Beast tries to fight against Riku, but Riku quickly sends him off to the side. Sora arrives and prepares to fight against Riku, but he simply steals the Keyblade saying there can only be one Keyblade master and that Sora was only the delivery guy. Riku leaves before Sora can try to get the Keyblade back. Since their orders were to stay with the Keyblade master, Donald and Goofy sadly follow after Riku while Sora sticks with Beast. Meanwhile, Maleficent , having gathered all the princesses of heart, asks them to reveal the Keyhole.