Lost item

A lost item is a special item in that randomly appears on the ground outside. Belonging to a random villager in town, the player can ask any villager if they lost an item. If the villager did lose the item, then the player will be rewarded with fruit, clothing, or furniture. If the item does not belong to that villager, they will return it and wish the player luck. It appears in multiple different forms around the town including a book, brown bag, and a mitten. If the item given is a fruit, it will not be a Perfect Fruit. Lost Items cannot be thrown away, sold, or dropped once picked up. There can only be one lost item in the town per day that may be returned to a villager.

If the item is not returned within a day, it will change in the villager's inventory to an item titled "What was this?". The only option will be to open it. This means that players can choose to keep the lost item and forgo increasing friendship with a villager. If the player sells the lost item to Reese, it will cost Bells to sell it.

Not delivering the item on time will lower the friendship between the player and villager, most likely the same amount as denying a request from a villager.

While lost items have not appeared outside of, the key in is seen as a precursor to this mechanic.

Key
In, a key is an item that a villager uses to get into his or her house. From time to time, a villager will be seen walking only around the outside of their house and will state that they are locked outside and has lost the house key somewhere around town. The villager may further reveal the location, which is the river - including the waterfall and lake. The key can only be found after the player has talked to the villager.

The key appears as a small fish shadow in the river, about the same size as a crucian carp. Once the player has fished it out the river and returned it to the villager, the villager will give the player a small reward, usually furniture, a gyroid, or a small amount of Bells.

If the player fails to find the key, the villager acts normal the next day, suggesting that they eventually found a way into their house.