From Bulbapedia, the community-driven Pokémon encyclopedia.
Yuma (Japanese: ユマ Yuma) is a Pokémon Breeder who appeared in the episode What I Did for Love!. As well as being a Breeder, she has put her skills into being a Pokémon Coordinator and is a former winner of the Grand Festival. Her current mission is to pass on her skills to beginning Coordinators.
In the episode, she meets Brock and is instantly impressed with his Pokémon and Pokémon food. She suggests he enters the Gardenia Town Pokémon Contest and, infatuated by her, Brock quickly does so. After his appeal, she asks him to study with her after the Contest. However, on seeing the Battle Round she decides that Brock is already too good for her and trains Mollie instead.
She does not appear to be bothered about Brock's feelings towards her and just laughs at his consistency when he flirts with Nurse Joy in the middle of his appeal.