Professor Ivy runs the Pokémon lab on Valencia Island in the Orange Islands. She's good friends with Professor Oak, and when Ash's group stopped by her place, things got interesting—they were there to pick up some mysterious Pokéball, and it was during that visit that Brock decided to stick around and stay with her.
What actually went down between them remains a mystery to this day. Fans have speculated endlessly about why Brock eventually left, but it's never been officially explained.
She popped up briefly in the second Pokémon movie and got a name-drop in the English dub of the seventh film.
Content compiled by AnimeList.moe from publicly available sources.
