Crown

The Crown is a new costume modification introduced in Kingdom Hearts II Final Mix. The Copper Crown is obtained when Sora acquires his first Proof, and as he gains more Proofs, it is upgraded to the Silver Crown and then Gold Crown.

The Proofs are key items which are obtained as rewards for clearing certain side-quests that were introduced in Kingdom Hearts II Final Mix.
 * The Connection's Proof (つながりの証) is a sphere like object that has a keyblade engraved on it. It proves that the player has defeated the Lingering Sentiment.
 * The Non-existent Proof (存在しない証) is a sphere like object that has a nobody insignia engraved on it. It proves that the player has defeated each of the Organization XIII Replica Data.
 * The Tranquil Proof (安らかなる証) is a sphere like object that has a face of one of the Mushroom XIII engraved on it. It proves that the player has satisfied each member of the Mushroom XIII.

Excluding in-game cutscenes, the crown appears on Sora's head regardless of what form or situation he is in.