The theme features memorable stained glass emblems of Sora, Ventus, and Vanitas. You can see the theme below:
UPDATE 1: The theme is also available to download on the Japanese PS Store!
UPDATE 2: Although previously stated by Square to be available on February 28th, it seems like the theme will be available internationally after the release of the game if you pre-order.
UPDATE 3: Kingdom Hearts HD 1.5 + 2.5 ReMIX is now available on the Japanese PlayStation store! Check out the store icon below: