Where are You?
You might expect the moon’s interior to be some sort of creepy dungeon, but such is not the case. Instead, you find yourself in a big grassy field on a sunlit day, with a big tree in the distance. What a trip!
Approach the tree to find a group of children frolicking around. Only one of the kids isn’t playing: the one who sits near the save statue, with Majora’s Mask on. Ignore this child for the moment, and save your game.
After saving, speak to the child who’s wearing Odolwa’s Mask (the tribal mask worn by Odolwa, the boss of Woodfall Temple). The child likes your collection of masks and asks if you’ll sell him one. Go ahead and give him a mask that no longer holds much use or value. Don’t give the child a mask that gives you a special power, though, for those might still be of use. (For example, the Blast Mask and Bunny Hood are worth keeping, as they may come in handy.)
Give the child a mask, and he’ll consider you a nice person. He’ll invite you to play a game of hide-and-seek, and you’ll be whisked away to a new area.