Sanae

Olesia is a character of the day who appeared in No Big Woop!. She built and runs the Wooper Pond Preschool, a Pokémon Day Care that specializes in Wooper.

As a child, Olesia revealed that she has always had an affinity for Wooper, so she decided to establish the preschool facility. A group of wild Wooper appeared at the pond one day and still continue to frequent the area. She has since trained all of the Wooper to follow the beat of a tambourine, and she also provides them with regular meals.

After learning that her mother broke her leg, she rushed off and left Ash and his friends, whom she then just met, to take care of her Wooper while she visited her mother in a nearby town. She later returned, with Brock on her motorcycle, just as Team Rocket had captured her favorite Wooper with a heart-shaped marking on its torso. Olesia and Wooper took care of the evil trio and sent them blasting off, much to the surprise of Ash and his friends. Brock was keen to learn Olesia's secrets after witnessing Wooper's incredible strength, and she revealed that there was no secret and that Wooper are simply misunderstood by most people for being small and weak.

(Source: Bulbapedia)