This page explains how to solve the quest "Trying to Laugh" in Yo-kai Watch.
Start the Quest
Talk to the girl in the Hot Springs to start the quest.
Let's hear some jokes!
Go into the guys section of the Hot Springs and talk to the guy to hear his bad jokes.
Get some Yo-kai help!
You need to get a Heheheel medal to continue the quest. It is a Rank D Yo-kai that can be found in Catfish Pond. It can also be found in Downtown Springdale in the Construction Site at night. Its favorite food is meat, so if you have access to Flower Road in Shopper's Row, you can buy meat from the meat shop there. Then when you encounter a Heheheel, before you tap Fight, tap Items, then choose some meat and choose "Use on Foe" to give it to Heheheel before you attack. This will slightly increase the chance that Heheheel will befriend you after the battle.
Quest Complete
After you have a Heheheel medal, go back and talk to the girl in the Hot Springs to complete the quest.