After obtaining the Yo-kai Watch on Mount Wildwood and befriending some Yo-kai, Whisper follows you home.
An Invisible World
You come home to find that your parents are arguing. Whisper says that there is actually a Yo-kai making your parents fight.
When the radar is showing a strong reading, press Y to open the Yo-kai Lens. Move the lens around like you did before, and you will soon find Dismarelda. Talk to her.
Cadin will try to fight her, but he's not strong enough. Whisper says that you have to go befriend at least three more Yo-kai before you will be able to fight Dismarelda.
Go outside. You will see a message that some Yo-kai won't want to be friends unless you give them a food that they like, making them friendlier.
Make Five Fast Friends!
Whisper gives you three Plum Rice Balls and says that you can get more at a convenience store. Be sure to go to the convenience store and talk to Eyepo to heal up your Yo-kai. You should also buy some things at the convenience store to throw at the enemy Yo-kai to try to make them friends.
After you have caught some Yo-kai, Whisper will say that he senses a powerful Yo-kai in the fish market.
The Fish Place is in the southern part of town. Go there and talk to the Fish Seller, who is standing out front. Based on what the fish seller says, Whisper thinks that there is a Yo-kai somewhere around the crosswalk.
Someone at the Fish Shop
Press the crosswalk button and wait for the light to turn green, then cross the street. Use the lens in this area to find a Yo-kai at the corner. Talk to it.
You will see a cutscene where the cat-like Yo-kai tries to attack a passing truck, but gets knocked away instead. You learn that this Yo-kai, Jibanyan, used to be a regular cat, but was hit by a truck. His former owner, Amy, was disappointed in him for it. Ever since then, he has been trying to defeat trucks so he can show Amy, but he hasn't succeeded. On top of that, a gang of Yo-kai behind the Fish Place stole his picture of Amy. You and Whisper decide to get the picture back.
Press the crosswalk button and wait for the light to turn green, then cross the street. Go around the right side of the Fish Place and enter the alley.
Get the Pic!
In this dangerous location, you won't be able to use your diary.
Go to the left and open the yellow box to get a Small Exporb. There is a Negatibuzz floating around here. Then go to the left and open the purple box to get a Plum Rice Ball.
Go down and talk to the Yo-kai there. It's holding the picture of Amy, and it won't give it up without a fight. You will have to fight three Roughraffs. You can't use items on these enemies. Afterward, you get the Photo of Amy.
Go north and you run into Detective Holdit. He says that the Yo-kai you just defeated was one of the most wanted. He decides to make you an official Yo-kai investigator. He will go to the Lambert Post Office.
About Yo-Criminals
Starting at 6AM every day (based on your system clock), the weekly Yo-criminal will be hiding somewhere in town. They are often on roads, but not always. When you find one, it makes a sound and runs away. Run after it (use Staminum to run longer if you want) and when you are close enough, talk to it. You will catch it. It will then disappear until 6AM the next day.
After you catch a Yo-criminal three times, it reveals a letter of the weekly secret password. You can only get up to two letters of the password per week, so you will have to talk to other players to find out what the other letters are.
When you know the full password, use the second window at the post office to enter the password.
Detective Holdit can tell you the deadlines for catching the Yo-criminals.
Back to the Story
Now leave the alley the way that you came in, and go back to the crosswalk. Cross the street and talk to Jibanyan. After giving him the photo and some words of encouragement, you get Jibanyan's medal. This activates one of the special seals in the Medallium.
Revenge on Dismarelda!
First, you might want to go south to the Lambert Post Office, where you can talk to Eyepo in order to heal up and swap Jibanyan into your party. You might also want to visit a convenience store to buy some items.
When you are ready, go back into your house and talk to Dismarelda. You'll call Jibanyan, then after he recovers from hitting the ceiling, you fight.
If any of your Yo-kai become Inspirited, rotate the wheel to put the Inspirited Yo-kai into the back, then tap purify and follow the instructions to purify the Yo-kai.
Time to Make Up
After the battle, Happierre appears and makes your parents stop fighting. Then you find out that Happierre and Dismarelda are married, and had an argument too.
Dismarelda apologizes for Inspiriting your parents and gives you her medal. This activates another special seal in the Medallium.
After this, your parents apologize for arguing, and you all decide to make dinner together.
Now you can use the Crank-a-kai in front of the Sacred Tree on Mount Wildwood. That's where you met Whisper. SpotPass is also unlocked. You can go to the Post Office to use it.
The next day, you remember that you are planning to meet with your friend at Triangle Park. This begins the chapter Protect the Seals!