Zelda Infinite

After giving the letter to the guard in Kakariko Village, the Happy Mask Shop will be open for business. It's in Hyrule Market. Go in there and the Happy Mask Guy will hire you. At first you can only get the Keaton Mask but eventually you'll unlock more masks.

	Keaton Mask The Keaton Mask is the face of a popular character in Hyrule. The guard in Kakariko Village wants it for his son. Go there and give it to him and he'll give you the 10 rupees required and 5 rupees extra(yay..). Now head back to the Happy Mask Shop.
	Skull Mask The Skull Mask is well...a skull mask. A Skull Kid in the Lost Woods wants it. He's not very hard to find, just head left when you enter the Lost Woods. If you haven't done it already, stand on the stump and play Saria's Song to get him to be your friend. Then L-Target him and speak while you have the mask on. He'll give you 10 rupees but it isn't enough so you'll have to shell out the other 10. Now head back to the Happy Mask Shop.
	Spooky Mask This Spooky Mask is the mask of a ReDead and is the perfect accesory for scaring someone. The little kid in the Kakariko Graveyard wants it so he can be as scary as Dampe. Tough luck kid....He's only there in the daytime and will pay you the full 30 rupees for the mask. Now head back to the Happy Mask Shop.
	Bunny Hood The Bunny Hood is basically a headband with rabbit ears. Unlike in Majora's Mask, it doesn't make you run any faster. The running man of Hyrule wants this mask. He's in Hyrule Field and will only appear after you defeat the boss in Jabu Jabu's Belly. He'll be running around clockwise on the yellow path, so run counter-clockwise to find him. As payment, he'll fill up your wallet to the max, so the max amount he can give you is 500 rupees. Now head back to the Happy Mask Shop.

Now that all the masks have been sold, your task is complete. You can now borrow any mask for free at anytime while you're a kid. You'll also notice that you've unlocked four different masks; The Goron Mask, The Zora Mask, The Gerudo Mask and The Mask of Truth. The Mask of Truth allows you to speak to Gossip Stones and get hints from them, while the other masks are just for fun.

Before you start the trading sequence as an adult, I strongly recommend that you get Epona the horse because some of the events are timed. After getting Epona, head down to Kakariko Village. Also, while doing the timed events, DON'T USE WARP SONGS! If you do, your item will automatically expire.
	Kakariko Village Head to the north-east center of town where the Cucco Pen is. You'll see Anju there. Talk to her and accept her request to hatch the egg and make it happy. After you've got hatch the egg (wait until 1 full day passes or play the Sun's Song twice) go into the house with the box in front of it. You'll see Talon on the bed. Wake him up with the Pocket Cucco and then it'll become happy. Now head back to Anju and accept her request to take Cojiro to her brother.
	Lost Woods Head down to the Lost Woods and take the left entrance. You'll see a man by the stump where the Skull Kid once was. Use Cojiro on him and he'll wake up. He'll give you an Odd Mushroom to take to Old Hag in Kakariko Village, but you only have 2:00-3:00 minutes! Get on Epona and go to Kakariko.
Kakariko Village The quickest way to the Old Hag is via the Potion Shop. Go in there and use the back door and then go into the house next to it. If it's nighttime, the Potion Shop won't be open and you'll have jump over the fence near the WindMill.
	Old Hag's Shop Talk to her and pull out the Odd Mushroom. She'll ramble on about Anju's Brother and then give you medicine to take to him. Since it's not a timed event, you can take your time.
	Lost Woods Go to where Anju's Brother was and you'll find a blond Kokiri. She'll tell you that Anju's Brother turned into a Stalfos and will get angry at you for taking the mushroom from the forest. Give her the medicine and she'll give you a Carpenter's Saw.
	Gerudo Valley Gerudo Valley is near Lake Hylia, so head there. You'll see that the bridge is broken. There are two ways to get across. One is to use Epona to jump across the bridge and the other is to use the LongShot to pull yourself across. Once you're on the other side, give the Saw to the Head Carpenter. He'll give you a Broken Sword (how nice). Now take this to Biggoron.
	Death Mountain To reach Biggoron, you're gonna have to go ALL the way up to the top of the mountain. Once you reach there, give him the Broken Sword and he'll tell you that he can't fix it because his eyes hurt. He'll give you a prescription to bring to King Zora.
	Zora's Domain Head down to Zora's Domain and give the prescription to King Zora. He'll tell you that he doesn't have any EyeDrops but he has the EyeBall Frog required to make it, but it will expire after 2:00-3:00 minutes so you've gotta hurry to the Laboratory at Lake Hylia.
	Lake Hylia If you made it in time, talk to the scientist here and give him the EyeBall Frog. He'll give you Biggoron's EyeDrops but yet again, it's a timed event and you've only got 2:00-3:00 minutes! This is the hardest of the time events, so I'll give you a good shortcut.
Lost Woods/Kokiri Forest From the bridge that leads to Kokiri Forest/Hyrule Field, look to the side and you'll see a ladder. Use the LongShot to reach this ladder and climb up. Now head straight for the warp that leads to Goron City.
Goron City Go into Darunia's Room and go through the hidden passage behind the Statue.
	Death Mountain Crater From here, work your way up to the entrance and go through. You'll find yourself on Death Mountain Summit next to Biggoron. Give him the EyeDrops and he'll give you a Claim Check for the Biggoron Sword. You can either wait 3 days or play the Sun's Song times for 3 days to pass. After those 3 days, return to Biggoron, present him the Claim Check and he'll give you the best sword in the game, The Biggoron Sword. This sword is longer and more powerful than the Master Sword but you can't use your shield while using it so beware.