Here's how the event works:
* You need to complete the main story.
* Talk to a specific NPC: After beating the game, you'll find a woman in Floccesy Ranch who will give you a unique item called the "Treasure Hunt."
* Use the Treasure Hunt item: This item will allow you to find dropped items from other players throughout the world.
* Dropped items: You can find a wide variety of items, including held items, evolution stones, rare berries, and even Pokemon!
The dropped item event is a great way to find rare and valuable items, and it's something you can continue to enjoy even after you've finished the main game.