In Chuckola cave, there is a firebrand turtle. Knock it over and you'll find a secret
area. Inside it, find a path leading down. You'll need to pay 500 coins to start the
minigame, Chuckola Bounce. If you win, you'll get a keycard. Show it to the first snail
you saw, and you'll have to fight Popple (not Rookie) for the first piece.

It´s your choice: you can start the recover like Gwahar Lagoon, Winkle Area of
Chucklehuck Woods, missions from Yoshi theatre or the S.S. Chuckola shipwrecked in Teehee
Valley. Depends!