Master Yen Sid
After the opening scene search the area for three chests containing Cure, Pulsing Crystal and Balloon Letter then enter the tower. Open the chest under the steps for a Magic Recipe then head up the steps. After the scene return to the Mysterious Tower and grab the Balloon Sticker by jumping and swinging the Keyblade. On the World Map head to the area listed as "???" for a few brief scenes. Afterwards head to the city of light, Radiant Garden.