From Bulbapedia, the community-driven Pokémon encyclopedia.
(Japanese: J) is a Pokémon Hunter(ポケモンハンター that steals trainer's Pokémon. She first appeared DP020. Her Japanese voice actress is 本田貴子 Takako Honda.
This listing is of J's Pokémon as of the most recent Japanese episode:
It is unknown if she and the Pokémon Hunter's will be recurring characters.