Professor Araragi is the Pokémon professor of the Isshu region and notable for being the first female professor in the main series games. She's the one who hands out the starter Pokémon—Tsutarja, Pokabu, and Mijumaru—to new trainers.
While she made history in the games, the anime got there first: Professor Ivy of the Orange Archipelago appeared over a decade before Araragi, making her the franchise's first female professor overall.
Content compiled by AnimeList.moe from publicly available sources.