In Story of Seasons: Pioneers of Olive Town, you’ll find round, pink creatures bouncing out of crops. These are Harvest Sprites.
You can find Harvest Sprites from doing just about anything around your farm: harvesting crops, tilling land, mining, logging, and cutting weeds. Very early in the game, there isn’t much to do with the Harvest Sprites, but as you collect more, you’ll unlock more to do with them.
Once you find 25 Harvest Sprites, you’ll be able to visit the Earth Sprite Village where tons of different sprites will give you materials, food, and fish. The more sprites you assign, the more goods you’ll get back, and the higher quality they’ll be. Make sure to visit Earth Sprite Village frequently to pick up goodies, as doing so will level up the Earth Sprites, allowing them to bring you even more stuff.
At first, you’ll only have access to three of the sprites: the Grass Sprite, Stone Sprite, and Log Sprite. You can unlock more using Harvest Coins.
For every Harvest Sprite you find, you also get a Harvest Coin. Once you find 100 Harvest Sprites, the Harvest Goddess will awaken, allowing you to spend your Harvest Coins at the shrine to the north of Olive Town. Here, you can upgrade your stamina, improve your farm’s soil quality, unlock more sprites to give you more goodies in Earth Sprite Village, and even unlock special plots of land that will allow you to plant certain crops year round.