Destiny Islands

Destiny Islands is a world from the Kingdom Hearts series. It is the home world of Sora, Riku , and Kairi (although she was only raised there), the three main characters of the games. Destiny Islands is a chain of small islands although only two have been shown so far-- and only two can be accessed by everyone.

The Main Island
The Main Island is where the residents lived and went to school; Kairi is known to have attended one. The main island also has a small beach and dock. There is a fairly large town with a long clay path leading to the beach. Sora 's House is located among the town. Currently, a train from Twilight Town goes directly into this town through a small station.

The Small Island
The Small Island where ( Sora, Riku , Kairi , and the other residents of the island used to play) is a relatively small island. It is only reached by canoe or small boats from the main island. Most of the island is covered in trees and shrubbery. The outskirts are naturally covered in yellow sandy beaches. There is a Seaside Shack and a somewhat treehouse built into a large tree. A miniature island is settled next to the island and can be reached by crossing a bridge (which can be accessed by using the stairs in the Seaside Shack mentioned above or alternatively, by swimming towards a ladder on the opposite side of the island, and then climbing it). On that island is a crooked palm tree that grows Paopu Fruits. Local myth dictates that the two people who share one will have their destinies intertwined. The Cove at the back of the island has an obstacle course which Sora and Riku used during their competitive challenges.

The Secret Place is a cave hidden behind the island's waterfall. Sora and Riku first discovered it when they were young children and as such claimed it as their own. There is a door in the cave which is actually the Keyhole of the world. The cave's wall are covered in chalk drawings drawn by Sora, Riku , and Kairi depicting many things. Among them is a drawing of Sora and Kairi sharing a Paopu Fruit, as well as drawings of Donald, a chocobo, Disney Castle, and a monster coming out of a swirling ball.

Original Canon Story
In Kingdom Hearts :

Destiny Islands is the first world introduced, showing up in the opening FMV, where Sora is swallowed by the tide while trying to save Riku, and is transported to another world. This serves as a metaphor for the rest of the story.

When Sora awakens from his Awakening, he meets with his friends Kairi and Riku. The three are planning on building a raft and setting sail across the sea to find other worlds away from the island. Destiny Islands is a small world, which often leads to the boredom of its inhabitants, especially Riku, who desired to leave the islands and see the other worlds out there. Tidus once said that once you sail a certain distance from the islands, you simply can't go any further, but the other islanders believe he merely turned back and made up the story.

While gathering materials for the journey, Sora climbs into the Secret Place - a tiny cave on the island where the children scratch drawings onto rocks - and met a figure in a strange cloak who told him cryptic messages about the time to come. Sora's confusion lasts long into the night. Resting up in his bedroom, he sees a dangerous storm approaching, and hurries off the island to save the raft.

Upon arriving on the second island, Sora discovers his friends came too, but only finds Riku, who confuses him further by telling him to accept the darkness, and encounters an apparently-ill Kairi in the Secret Place. The two disappear in the growing darkness, but Sora returns as the Islands slowly crumble into darkness with the Keyblade in hand. He fights with the Darkside boss, but fails to save his home, and is whisked away on his journey to Traverse Town.

As his first journey ends, Sora and Kairi meet up on the shores of the reforming islands. Sora, knowing that his job is not finished, and that he must still save Riku and King Mickey from the Realm of Darkness, leaves Kairi in the safety of her hometown and promises to return to her as soon as Riku and King Mickey are found.

In Kingdom Hearts Chain of Memories :

During Sora's stay in Castle Oblivion, both Sora and Riku are presented with cards to open a memory version of their island; in Sora's version, he is separated from Donald and Goofy and left to make his way through the world without them. Naminé manipulates his memories to make Sora believe she also lived on the Destiny Islands, but eventually tells Sora the truth about Kairi and her in his memories of it. Zexion, in the guise of Sora, fights with Riku on a memory version of the Islands.

During Sora's sleep, the residents of the Islands forget all about Sora, due to Naminé breaking the chains of his memories. Kairi, however, being so close to Sora, still retains vague memories of the boy, and begins to remember before anyone else. She sends a message in a bottle across the sea, hoping to find Sora.

In Kingdom Hearts 358/2 Days

Roxas is seen near the bent palm tree with Axel looking in the distance while talking. Xion is also known to have visited the Destiny Islands, as a scene showing a discussion between her, Axel and Roxas has been revealed to exist. Xion has also been seen on Destiny Islands speaking to Riku, and it is implied that the seashells she brought Roxas while he was unconscious came from the islands. During Xion's nightmare, she transforms into Roxas, Riku, and Sora while listening to the hurtful speech Zexion gave Riku in Re:Chain of Memories near the bent palm tree.

In Kingdom Hearts II 

In an attempt to draw Sora, and with him, Roxas, back to the Organization XIII , Axel goes to the Islands to kidnap Kairi. She refuses to go with him, and flees with Pluto into a portal to Twilight Town.

Finally, after Xemnas is defeated, all the characters meet up on the Islands for one last time. Mickey, Jiminy, Donald, Pluto, and Goofy return to Disney Castle, and leave the others on the Islands. But, in an extra video after the credits, it is seen that Mickey sent a letter in bottle back to the islands for Sora, Riku, and Kairi. It is still unknown what it says, though its contents may be lapsed into being revealed in the future. Also, with Organization XIII and the Nobodies defeated, this world can be considered the new home for Roxas and Naminé.