(A wizard [Jumon] is shown flying through Hyrule. He stops at the Gerudo Fortress and casts a spell on Ganon. The screen goes dark and then shows Hyrule Castle. The wizard casts a spell on Zelda and hides. Link, who is in Hyrule Castle Town, hears about the wizard and rushes to Hyrule Castle. To his surprise, Zelda is now a 4-year-old. The wizard appears and casts a spell on Link, who begins to get younger until he's a 5-year-old. The wizard disappears. Impa enters and sees that Zelda and Link are little kids.)
Impa: Link, you must find a way to reverse the spell. That wizard goes by the name of Jumon and he casts spells that weaken others in odd ways. Causing youth is just one of his many hexes. He has the ability to shrink and transform anyone!
(BL nods and walks a few steps, then falls over)
Impa: I will stay and protect the princess. Take the Tyke Sword. (gives BL the Tyke Sword) You'll need it. You should travel all over Hyrule to get the Nine Mood Gems. Jumon first came into power in the realm that he is from. The realm no longer exists, but they made the Mood Gems to weaken him. Unfortunately, they also needed another holy power, the Triforce. When that realm fell, the Mood Gems were brought to Hyrule, hidden deep within temples. These temple are only accessible by those cursed by Jumon, though the only ones who would be able to get through the temples would be those cursed with youth. The first temple, the Temple of Joy, is located in Kokiri Forest. I'm afraid I don't know where in Kokiri Forest, but you're a smart boy. You'll figure it out.
BZ: Wink! You gotta go now! Take Wooden Toy Shield wif you! (gives BL the Wooden Toy Shield)
Impa: Don't worry. I'll take you there.