It is not news to any fans that Leonard Nimoy, know for his iconic role as Spock in the sci-fi franchise Star Trek, voices Master Xehanort in Kingdom Hearts: Birth By Sleep. It is also well known by the fandom that Mark Hamill, who is best known by his role as Luke Skywalker in the Star Warsfranchise, voices Master Eraqus in the same game.

Something not many know is that Nomura personally requested for the both of them to voice their respective characters because of their past roles as Spock and Luke Skywalker.

Final Fantasy characters were included in Kingdom Heartsto play roles that were not possible for Disney characters to play.

Leon was decided to play the role of the "guiding swordsman" who'd lead Sora in the right direction on his journey. However, if people immediately saw his original name (Squall) in Mickey's letter before actually meeting him, it would take away all of the suspense and the impact would be greatly weakened. Event Planning Director Jun Akiyama suggested to change his name for that reason.

KH1 Animation Director Tatsuya Kando had counted the total number of animations used in the game, including those that were cut with unused event scenes, reaching a total of almost 8000. He refers to these animations as "animations of the heart".

Haley Joel Osment, voice actor of Sora in the Kingdom Hearts series, has done work in various movies throughout his career. One of the more popular movies he has appeared in is Artificial Intelligence, a 2001 science fiction drama where HJO plays a human child-like android with the ability to love. His one wish is to become a "real boy", just like the story of Pinocchio, so David goes on a journey to find the Blue Fairy.

The original scenario of Kingdom Hearts involved Sora going to rescue the Princesses of Heart with their respective "princes".

Nomura was in a room speaking with Hironobu Sakaguchi (if you don't know who he is, go take a look at Final Fantasyhistory~) about what kind of game he wanted to make, of which he had an idea in mind for an action game with stylized characters. Shinji Hashimoto and a Disney employee was speaking together in that same room, and the Disney employee liked the idea, and proceeded to suggest the use of Disney characters that are known worldwide because they're stylized.

Popular British actor Tom Felton, well known for his role as Draco Malfoy in the Harry Potter series, is seen posing with vvmasterdrfan at Dragon Con 2009, posing with the fan's handmade Bond of Flame Keyblade from Kingdom Hearts II. He did not however, know what Kingdom Hearts or Keyblades are.

During the early development of Kingdom Hearts II, the final battle against Xemnas was planned much differently than the one that we all know. Xemnas was to meld with The World That Never Was after absorbing power from Kingdom Hearts and become a Transformer-like creature. After you defeated him once, he would transform into a much more distorted version of this creature. You can see concept art from the Kingdom Hearts II Ultimania below, which show how this original idea would have looked.

Composer Yoko Shimomura decided on Italian lyrics for the chorus of "Destati" as it was a language that could be listened to and not understand immediately like with English or Japanese. Other languages considered were German and Latin.

Although there are only 76 tracks on the KH1 Original Soundtrack, Shimomura actually composed 99. Why 99? Because she didn't want to have more than 100.

All together, Kingdom Heartshas over 15,000 individual sound tracks in the game. Note that sound tracks include things like the sound of footsteps, the clinking of the Keyblade's keychain, and other sound effects.