Mickey is the King of Disney Castle. Like Sora, he wields a keyblade. Donald Duck and Goofy searched for him in the first game.   He is voiced in English by Wayne Allwine and Takeshi Aoyagi in Japanese.

Sora is a young energetic boy looking forward to exploring the world with his friends, Riku and Kairi. The threesome is working hard on completing a raft that will allow them to leave their island but one day a mysterious force causes Sora to gain a special weapon known as the Keyblade. He fights some weird monsters and gets transported to a strange town. Meanwhile, Donald and Goofy leave their castle to search for the king and the chosen one who holds the "key" to saving the world. Sora is attacked again by creatures known as Heartless but is helped out by an old man named Cid and a warrior named Leon. He eventually meets up with Donald and Goofy and they join forces to go search for his friends and the King. 
(Source: Tokyopop)

The door to Kingdom Hearts was sealed, dealing a blow to the heartless and restoring the worlds to normal, but Riku and King Mickey were trapped inside! Now Sora, Donald, and Goofy's search for their friends leads them to the mysterious Castle Oblivion, where a hooded figure tells them, "Ahead lies something you need, but to claim it, you must lose something dear." What could be more dear than their very memories themselves? And what do the shadowy members of Organization XIII want with them? (Source: Tokyopop)

In the quiet little hamlet of Twilight Town, there lives a boy named Roxas. He and his friends Hayner, Pence and Olette are trying to enjoy their final days of summer vacation, when strange things begin to happen. First the group is falsely accused of stealing photos from all over town. Then they are attacked by bizarre, white creatures. But the oddest occurrences are the recurring dreams Roxas has of a boy named Sora, and the presence of a girl named Namin&eacute;, who has a mysterious secret to share with Roxas. 
(Source: Tokyopop)

The pitiful Heartless crave for hearts. The rage of the Keyblade unleashes those hearts. Hearts gather in the darkness, and eventually create Kingdom Hearts; to create the sanctuary for those lost hearts, those are Kingdom Hearts. Roxas, without any memory regarding his past, has been accepted into the Organization XIII. The privilege of becoming a member of the Organization XIII comes the responsibility that each member upholds. However a question arises: "Why am I in the organization?" On top of the clock tower with the sunset in the horizon, the 14th member, a young girl, makes this question. Who is this young girl, and how does she fit into the plot? This is the revitalization of Kingdom Hearts; the new prequel that connects the puzzle pieces of the mysteries that still float about. This is Kingdom Hearts: 358/2 Days! 

Wanting nothing more than to be a dancer, Rin joins a troupe with her fellow students and soon realizes that she has two left feet. She practices and practices, but is discouraged by the lack of results and almost gives up on her dreams. Impressed by her passion and dedication, Tinker Bell appears to give her a little encouragement in the form of a little Disney magic! Now with the help of Tinker Bell's magic cards, Rin can call upon the help of her favorite Disney characters and dance her way to her dreams!

Ten years before Sora fought to save the worlds, three young Keyblade wielders named Terra, Aqua, and Ventus trained in the hopes of becoming Masters one day. But everything changed on the day of Terra and Aqua's Mark of Mastery exam, and the three each set off on their own journeys that would test their friendship-and alter the course of their destinies forever.
 
(Source: Yen Press)

Promotional Video for the Disney mobile game Star Smash

"Sora, Riku, I would like the two of you to take the Mark of Master Exam."
Their journey to bring peace to the world just barely over, Sora and Riku have received news from Yen Sid regarding a new threat drawing near. In order to face this new world crisis, Sora and Riku must face the Mark of Mastery Exam. For this the must go to the "Realm of Sleep," release the seven Keyholes of Sleep, and gain a new power. 
(Source: Gold-Panner)

Mickey Mouse