Paper Mario: The Origami King introduces a host of new mechanics including Confetti.
Confetti is an interesting mechanic that will help you solve secrets, collect objects and gain access to new areas.
Here's how it all works.
Confetti
Confetti is gained in Paper Mario by defeating enemies, interacting with objects, finding confetti bags and even breaking them (this includes bushes, flowers, rocks, and broken statues).
In the top left of the screen, you will see a bag icon that shows you how much Confetti you have.
You need to use it on unfilled holes and objects that when filled in will often give the player coins. If you fill in these holes you can often find Toads hiding under them or it will grant you access to a previously inaccessible area.
Your Confetti Bag will hold up to 5 lots of confetti and will take about 3 throw to fill in a big hole.