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To get the Farore's Pearl talk to the Deku tree; and he says he'll start a ceremony with the Kokiris. However, one of them is missing so you must go to the Forbidden Woods and save him.

If you want the dungeon map go to the right and for a treat kill Green Chuchus to get Chu jelly. Then go to the right and get a big nut and then go to the center and throw it at the plant on the door. Now the plant should die so open the door…