After gathering the parts for Nathaniel/Kenny to make a Yo-Kai Watch, he gives you the Model Zero.
Yo-Kai Watch Model Zero
Nathaniel/Kenny gives you the Model Zero, but then he runs off. Go outside. Go south and talk to Hovernyan on the bridge.
Milk Bottle Tops
Go northwest and check on Faux Kappa, who has been turned to stone. After realizing that the curse is too strong in the past but is weaker in the present, Hovernyan gives you the milk bottle tops with the names of Nathaniel/Kenny's Yo-kai friends, and asks you to go to the present time to break the curse on those Yo-kai.
Go to the southeast of the area and use Mirapo to warp to Harrisville Station. Then use Miradox at the station to return to the present time.
Back in the present, use a Mirapo to warp to Grandma's House in Harrisville.
Talk to Gnomey near the altar in Grandma's house. He will give you a hint. Go outside and check on the chimney on the right side of the house. Then go back in and talk to Gnomey.
Find Faux Kappa!
Go northwest from Grandma's house in Harrisville, to the part of the river where you found the Faux Kappa statue before. Check on the statue. Defeat Faux Kappa in battle, and he will befriend you.
Go north from Grandma's house in Harrisville to Mt. Middleton. Walk north, and a cut scene will start.
Go north and climb the vine, then go northwest to the Cicada Canyon area. Go north and climb two vines, then go to the right and fall off of the edge. Climb the vine to the right, then go across the log. Follow the path to find the Pallysol statue. Check on it.
Go to the Temple of Virtue west of Grandma's house in Harrisville, and talk to the man out front. He tells you that the statue was seen at Excellent Tower.
Use a Mirapo to warp to the Everymart in Breezy Hills if you woke the Mirapo up there. If not, warp to Springdale Central Station, then go north to Uptown Springdale, then east to Breezy Hills, and continue going east to reach the Excellent Tower. If you can't warp to Springdale Central Station, you will have to take the bus from Harrisville, then take the train from Harrisville station. Remember to wake Mirapo up when you get there. Then follow the instructions earlier in this paragraph to reach Excellent Tower.
In the Excellent Tower area, go north to find the tower. Be sure to wake up Mirapo when you get there. Go inside. Go up and talk to the worker who is standing by the elevator. Then use the Yo-Kai Lens to find the hidden Yo-kai. Talk to him and defeat him in battle. Then talk to the worker.
Go into the elevator. Go to the northwest of the observation deck and check on the statue.
Go for Rank C!
You will need to upgrade your watch to Rank C if you want to find Mermaidyn. So go to Timers & More in Blossom Heights and talk to Mr. Goodsight to start the quest. Go northeast in Blossom Heights to find the Old Mansion. It is behind the Candy store.
Inside the mansion, you need to find specific Yo-kai that have blue flags over their heads. The random Yo-kai that look like red flames in the map will not count for the quest! In the mansion, go through the door on the right, then open the sliding door to the right and talk to Helmsman to battle him.
Go back into the mansion and go to the big middle room. Go through the big door in the back wall. Then go through the northwest door with the eye on it. Go up the ladder to the left, then go to the right and talk to Lafalotta to battle.
From there, go north and go down the ladder there. Then go east and open the sliding door, go south and east and then north to the pond, and talk to Slicenrice to battle.
After this, go back to Timers & More and talk to Mr. Goodsight to get your Rank C watch.
Go to the school southeast of Grandma's house in Harrisville. Go into the school building and go to the right. Go into the restroom and use the Yo-Kai Lens to find the hidden Yo-kai. Talk to her. Then go outside and talk to her. Agree to play hide-and-seek. Check the upper-right and bottom-right corners of the schoolyard. The others are easier to find.
After you win hide-and-seek, Toiletta tells you to look for Mermaidyn in San Fantastico. You can get there by train. The shortest route is to go to Harrisville Station and take the train to Fortune Place, then transfer to the Central Line going toward San Fantastico.
In San Fantastico, go southeast to reach a beach where a fisherman is fishing. Go north on that beach to find the cave entrance. Use the Rank C watch to open the gate. (Read the previous section if you don't have the Rank C watch.)
Go through the cave and you will encounter Wiglin. Go farther into the cave until Whisper senses something. Then use your Yo-Kai Lens to find a hidden Baffle Board. The correct answer is Wiglin.
You will need to befriend Wiglin to continue. A Wiglin will always appear near this Baffle Board, and if you defeat it without befriending it, you can just wait here for another one to show up. If you are having trouble, you can go to a Mirapo and warp to Shopper's Row to buy ramen from the ramen shop there. Ramen is Wiglin's favorite food.
After you befriend Wiglin, put the correct answer into the Baffle Board if you didn't already, then summon Wiglin to the hot spot in front of the Baffle Board. Then talk to Wiglin, and he will lower the water level in the cave.
After you lower the water, you can go southwest to find another hidden Baffle Board. This time, the answer is Steppa. You will have to befriend Steppa to proceed. Fortunately, there is always a Steppa in the south part of the cave. Use ramen (available from North Wind Ramen in Shopper's Row) to improve your chance of befriending him.
After you befriend Steppa, summon him to the Baffle Board, then talk to him. He will raise the water level, changing the path.
As you go along the path, you will see another seaweed Yo-kai. You will need to befriend this one, too. Her name is Rhyth. If she doesn't join you after the battle, just stay in the area and wait for her to reappear so you can try again.
There is another Baffle Board ahead, and Rhyth is the correct answer. Summon Rhyth, then talk to her.
After she lowers the water, drop down from the cliff and make your way north. Check on the statue. Cap'n Crash will attack.
He doesn't have multiple targets to stick a pin into like other bosses. Just attack him. After a while, he will bring out a ship's wheel. When he spins it, your Yo-kai will randomly spin, and you won't be able to spin them.
After you have lifted the curse from the five Yo-kai, use a Mirapo to go to Harrisville Station, and use the Miradox there to go to the past. Then use Mirapo to warp to Harrisville from there.
Go northwest to Nathaniel/Kenny's secret base and talk to Hovernyan. Then you will have to fight a boss.
Kin and Gin
The sisters can bring each other back to life, so after defeating one of the sisters, you have to defeat the other one quickly. Try to keep both sisters' HP close to the same by changing the target pin after attacks.
After you defeat them, there will be a cut scene. Then the next chapter, The Storm Is Here!, will begin.