Leave the Island
After completing Moonlit Grotto, go north to find some Tokay about to eat a large red dodongo called Dimitri. Give your ember seeds to the Tokay on the left to rescue Dimitri. Talk to him.
Now you can swim off of the island. You can find a new spot of soft soil. Go northeast to reach an island with four bushes on it. The bottom left bush hides a spot of soft soil.
When you get back to the shores south of Lynna City, Dimitri will swim away for now.
Get an Animal
Now you have met all three animals: Moosh, Ricky, and Dimitri. You can get one to permanently help you out when you call it. It's up to you which of these animals you want to befriend permanently, but once you do, you can't change it.
The advantage to having Dimitri is that you can sail the seas with him and swim up waterfalls. However, later on you will get an item that lets you do the same thing.
The advantage to having Ricky is that you can jump up cliffs. There is no item that lets you do this, so Ricky is pretty unique. His tornado punch is also very helpful. He is also very fast.
Moosh can float over gaps, but he is difficult to control. Being able to fly over gaps isn't as useful as it might seem.
I recommend getting Ricky, but it's your choice.
To get Dimitri, buy the flute from the shop.
If you want Ricky, play the Target Practice game in Lynna Village in the past to win the flute.
If you want Moosh, you can just go to Symmetry City and you will get him by default unless you get one of the other flutes as described above.
Go to Symmetry City
In the present time, use the west exit of Lynna City and go north. (If you are playing a Linked Game, you will see Impa outside of the Black Tower. She asks you to go on a rescue mission.) Go west from the broken bridge and give the Mask Salesman the Tasty Meat if you have it. Then go back to Lynna City and keep going east from the Black Tower entrance, then go into the house that you find. Give the Doggie Mask to Mamamu Yan, the woman in present-day Lynna City with the dog. This gives you the Dumbbell.
Go back to the broken bridge. Shoot the small tree across the gap with an Ember Seed from your seed shooter, then use another seed to flip the switch. Go across the bridge and go north. If you fall into the water below the bridge, jump down the waterfall and go around to get back to the bridge.
There are some flowers and bushes and two Buzz Blobs. Don't hit these monsters with your sword because you will get electrocuted and lose a heart.
Up ahead, walk north on the shallow water and you will find Mutoh, a carpenter whose workers are missing. You can't do anything in this area right now, so just go back toward Lynna City. A fairy from the forest will find you and say that there is an animal lost in the woods. Again, the animal who is lost will depend on whether you got one of the special flutes or not already.
Find the Lost Animal
Go to the woods. From the screen with the fairies, go up, down, and up. You will find the missing animal. If it's Moosh, he will give you a flute to summon him anywhere. If it's one of the others, it means that you already have the flute.
Now go back to the carpenter and agree to find his workers.
If you have Dimitri
If you have Dimitri, then after talking to the carpenter, go south, walk across the shallow water and go east. Swim up the waterfall to find the first worker. Jump off of Dimitri and talk to him.
Get back on Dimitri and go south, then exit to the east to find the second worker.
Go up the waterfall in this screen to enter a cave. Have Dimitri eat the lower Goponga Flower. Swim past where it was, then get a ring from the treasure chest in the upper area.
Exit the cave, go down the waterfall, then exit to the northeast. Go up the waterfall and exit to the north to find the third worker.
If you have Moosh
If you have Moosh, go talk to the carpenter, then go east, pound the ground next to the bush, then float over the holes to go up the stairs. Float over the holes in this area to exit to the north, where you find the first worker.
Exit to the south from where you found the first worker, then float over the holes so you can exit to the southeast.
Float to the right side of the screen, float down to the two bushes. Pound the ground next to the bushes to get rid of them, then exit south.
The cave entrance here leads to a ring. Float over the holes to go along the bottom of the screen and exit west. Then float up to go up the stairs to the north, and exit east. Follow the path to reach the second worker.
Go back the way you came. When you get to the screen with a bush to the left of four holes in a line, go north. Float over the holes to go up the stairs and exit north. Go east, then down the stairs and exit to the south. Float over the holes to reach the third worker.
If you have Ricky
If you have Ricky, go down and then right. Jump up the cliff and go north to find the first worker.
Go south and hop back down the cliff, and go north until you pass a set of gaps on the right with flowers and bushes between. Hold down the punch button to make Ricky charge up, then shoot a tornado punch at the bushes and flowers to get rid of them. Hop over the gaps and go northeast. There is a fairy fountain that you can access in this area. Go north up the stairs, then go to the right and head south. Use a tornado punch to get rid of the bushes past the gaps. Jump over and then jump up the cliff. Jump up the cliff above the cave entrance to find the second worker.
Go into the cave afterward and get the ring from the chest. Then go back the way you came and go west past the stairs. Before going south from the tree, go west to a screen where you can dig up a soft soil patch to plant a Gasha Seed. Then go back to the tree and go south to find the third worker.
Symmetry City Ruins
Now cross the bridge and make your way past some Darknuts to find the Symmetry City Ruins. There are some Fire Pokeys around, but you can kill them with three swings of the sword. Go west from the entrance to find a Gale Seed tree. These seeds allow you to warp to different trees around Labrynna that you have been to. If you cut the bushes around the tree you will find some dormant time portals that you can activate with the Harp of Ages. After exploring the ruins and the surrounding regions if you want to, activate one of these time portals and go to the past.
Go into the building and talk to the people to learn that Symmetry City requires left and right to be in perfect balance. The Tuni Nut (it's a palindrome!!) is broken, and the woman's husband has it, but he would need to climb Restoration Wall to ask the guru Patch to fix it, but he can't climb the wall.
Get the Tuni Nut
Downstairs, you will find a guy who wants to work out, but he only has one dumbbell. Give him yours if you have it. He'll give you a mustache.
Go to the northeast house and talk to the person inside, then talk to the person in the northwest house (you can do it in the opposite order if you prefer.) He will give you the broken Tuni Nut.
Continue the Trading Quest
You can find a time portal to the southwest of Symmetry City. Use it to go to the present, then use a Gale Seed to go back to Lynna Village. Give the mustache to the guy in the cape. You will receive the Funny Joke.
Then go to the past and talk to the boy in Lynna Village who, if you talked to him before getting the Funny Joke, says that laughter is a dream deferred. He's in the house in the past that is in the same screen as the man you gave the mustache in the present. The joke won't go over that well, but the boy gives you a Touching Book. The next time you encounter Maple, she will take the Touching Book and give you the Magic Oar.
In the past, go to Rafton's house and give him the Magic Oar. You get the Sea Ukulele. You won't be able to reach the person who needs the Ukulele yet.
Get the Tune of Currents
Go back to the present time and warp back to the Symmetry City Ruins, and then go back to the past. Go southwest from the town and follow the path. You will find an owl statue next to a time portal, but before you use it, go east from it, then make your way north, and walk to the small spot of deep water past the wavy line of shallow water. Dive into it and swim through the cave, killing the Cheep-Cheeps until you reach the ladder. Climb up.
This is Tokkey, who researches time. He's missing something to complete his research. Play the Tune of Echoes for him. He will finish the song and teach you the Tune of Currents. It allows you to go to the present from the past without the need for a time portal. It does not take you from the present to the past. When you travel to the present with the song, it will leave a sparkling spot where you played the song, and if you step into the sparkling spot, you go back to the past.
Now that you have the Tune of Currents, you might want to visit the secret shop in Lynna City in the present. It sells a bigger ring box, a piece of heart, and a gasha seed. To get there, go to Lynna Village in the past and go two screens south of the Maku Tree. Stand above the top-left corner of the middle trees and use the Tune of Currents. You will appear within the fenced-in area next to the shop. Go into the door and follow the path to the secret shop.
Go to Restoration Wall
Now go south from where you went underwater to find Tokkey, then west. You should be in a screen with a waterfall on the right, and three blue darknuts. Go to the bottom of this screen and use the Tune of Currents. You can get a piece of heart.
Now go to the screen in the past with the owl statue, but don't use the time portal next to it. Instead, go to the bottom-left corner of the screen and use the Tune of Currents. Then go down the stairs. The path through this area is straightforward. You will have to fight some Moblins and Tektites along the way. Eventually you reach a screen with vines going up the wall. Don't go up the vines. Go up the stairs. Pick up the rock to reveal a time portal. Use it. The Tune of Currents doesn't work in the present, so use the Tune of Echoes to use the time portal.
Go north into the cave entrance. Go up the stairs and out the east door. Push the strange red thing to change the water. Then go back into the cave, go down the stairs, and exit the cave. Use the Tune of Currents to go to the present. Go up the vines on the left and throw a bomb into the pond that says not to throw anything. Be honest and say that you threw a regular bomb. The fairy will increase the number of bombs that you can carry.
Now go down the vines and up the stairs, then use the sparkling point or the time portal to return to the past. Go down the stairs and push the vine sprout to the right and go back to the present. Climb the vines. Go east and go up the stairs to the northeast. After walking along a straightforward path with some moblins and tektites, you will reach a time portal. Use it to go to the past.
Go up the stairs and follow the straightforward path, which is much like the path that you went through in the present. When you reach the watery area, go down the stairs at the bottom left corner of the screen. Get past the blue Octoroks and exit to the east. You will reach Restoration Wall.
Climb Restoration Wall
Climb up the vines and avoid the falling rocks. Stay in the middle of the screen or you will reach a dead end at the top and will need to backtrack. Ignore the three openings at the top where rocks come out and climb onto the ledge. Go into the cave entrance at the top of the ledge.
Talk to the guy in the house. He is Patch, the restoration guru. Tell him that you need his help. He asks if you want to try his restoration ceremony. Say yes. It's more of a minigame than a ceremony. Go down the stairs and ask to do the ceremony.
The rules are that you have to knock the monsters into any hole. A mine cart will go around the room, and if it hits the Tuni Nut, you fail the ceremony. You can prevent the mine cart from hitting the Tuni Nut by standing on the switch. This changes the tracks so the mine cart will pass by the Tuni Nut and go around once more. But you still have to push the monsters into a hole to complete the ceremony.
It's easiest if you can get all of the monsters to clump together. One way to make this happen quickly is to first stand on the switch until the cart has gone past the nut once, then lure the monsters to the top right and then fall into the top right hole. When you reappear, you should end up near the top right, but you will have lured the monsters close to a hole where you can knock them in more easily. Remember to step on the switch if the cart is getting close to the Tuni Nut so you can make it go around again, giving you more time to complete the ceremony.
Restore the Tuni Nut
After you succeed, you are given the repaired Tuni Nut. Patch mentions that if you have anything else that is broken, you can bring it to him to do a restoration ceremony, so keep that in mind.
Now you can go back to Symmetry Village. Just go east or west, hop down the cliff, and go up the stairs, and you will be back in the village. Go to the building at the bottom middle and walk up to the pedestal to put the Tuni Nut back in place.
Now go outside and use the Tune of Currents to go to the present. Symmetry City will no longer be in ruins. You can go up to where the volcano was and there is now a cave. It leads to the next dungeon, Skull Dungeon.