Sora and the others lock the heart of Hercules' world and recieve a gummi block from one of the other contestants. Then, before they can move on to another world, they are swallowed whole by a giant monster and discovered by Pinocchio and his "father" Gepetto. Pinocchio has been gathering Gummi blocks so that his father can build a ship to survive being spat out by Monstro, the whale.
But when Pinocchio goes in search of more blocks, he is captured by a heartless, and Sora, Daffy and Goofy go to save him. There, they encounter Riku, who is controlling the heartless that kidnapped Pinocchio. Riku lays into Sora, saying that all he seems to be doing these days is showing off his keyblade. Does he really want to rescue Kairi? Sora says at least Pinocchio has a conscience, and his heart is telling him Riku is on the wrong side.
Riku leaves, and leaves Sora to fight the heartless. Maleficent tells Riku that unless Kairi gets her heart back, she will sleep like a doll forever. She tells him there are seven princesses, called the Princesses of the Heart, that when brought together can open a pathway to the world of the heart. If they can do that, then surely Riku can find Kairi's heart there. Riku says he will do anything to save Kairi, and Maleficent gives Riku the power to control the heartless. She and her raven share a smile...
Sora rescues Pinnochio and they and the others are expelled from Monstro. Sora, Daffy and Goofy's Gummi ship crashlands into an ocean world, where Ariel and her father are having a disagreement, as usual. She went outside the palace, against her father's orders, and is being chased by three heartless. Sora and company save her, and she takes them back to her father, who yells at her for leaving the safety of the palace. When he sees that Sora is the bearer of the Keyblade, he takes a dislike to him, and denies there is a keyhole here. Sebastian asks the King about it later, but the King won't discuss it with him.
Ariel takes Sora and the others to her secret grotto, but when they get there, it is destroyed, and her father is standing in the middle. Ariel thinks her father destroyed it, and flees, but after she is gone, he tells Sora that the heartless destroyed the grotto. He also tells Sora that the wielder of the keyblade brings ruin and death to worlds, which Sora disagrees with.
Meanwhile, Ariel has encountered the Sea-Witch, Ursula, who agrees to help Ariel journey to another world, if Ariel can bring her to King Triton's trident. But once she gets it, she turns the king into a sea-worm and tries to rule the seas. It's up to Ariel, Sora, Goofy and Daffy to defeat her. After everything returns to normal, King Triton has Sora lock the keyhole for his world, and tells Sora that the keyblade can bring ruin or salvation... it's up to the wielder. Therefore, he should use it carefully.
Sora also finds another page of Ansem's report, and faxes it to Cid, who sends them back the first page they found, translated. It was Ansem who first discovered the heartless and named them, and also made a machine to make heartless so that he could study them in greater depth. Sora and the others theorize that Maleficent found the machine and abused it.
They are interrupted when the ship collides with a pirate ship captained by Riku and Captain Hook. Kairi is there with them, but she is more like a puppet than a human. Riku says he controls the heartless now, and that his heart is too strong to be overtaken by them.
Sora and the others are imprisoned in the ship, where they meet Peter Pan and Tinkerbelle. They work with Peter Pan and Tink to rescue Wendy and Kairi from Riku and Captain Hook. But can they succeed? Will Sora and the others learn to fly? And can Sora save Riku from himself? All will be answered in the next volume!
The story continues to get darker, but once again, the juxtaposition of Disney Characters and manga characters is very strange. Because Ursula and Hook are more Disney and less manga-eque, the characters look very strange when they are shown in the same panel. Thankfully, instances of this are limited, but still, it makes for a strange mixture that is not as successful as the earlier volumes.
Some Omake (Extra) four-panel comics are included in the back of the book, all generally silly.
Tension is maintained in the story, and leaves readers wanting more. For such a short series, the creator did manage to pack in a lot of story into so few pages...