Andrea lives in Megi City on Yellow Rock Isle with her younger sister Mika and their dad, who runs a family business collecting Corsola horns for jewelry. The whole family showed up in "A Corsola Caper!"
Things went sideways when an overeager Corsola startled the rest of the colony, causing them to scatter. Since their house was literally built on top of where these Pokémon lived, the whole thing drifted away—with Mika still inside. Ash and his crew managed to rescue her, and when they heard what happened, Ash pitched in to track down all the missing Corsola. He pulled it off, and Misty even caught the Corsola that caused the whole mess in the first place.
She briefly showed up in a flashback during "Espeon, Not Included."
Content compiled by AnimeList.moe from publicly available sources.
