From Bulbapedia, the community-driven Pokémon encyclopedia.
Roman (Japanese: チアキ Chiaki) is one of the characters of the day in A Full Course Tag Battle! of the Pokémon anime.
He appeared along with his fiancée, Kylie. He is the owner of the Seven Stars Restaurant on the Valor Lakefront. Trainers must battle him and his fiancée in a Double Battle in order to eat in the restaurant for free.
Roman and Kylie first battled with Ash and Brock and were easily defeated by them. Then they were to battle May and Dawn. But before they could battle, Team Rocket broke in the restaurant and stole all the food. Roman was upset by this and wondered what his father would say.
After May and Dawn dealt with Team Rocket, Roman and Kylie started their battle with May and Dawn. Despite putting up a good fight, they were defeated in the end.
This listing is of Roman's known Pokémon in the anime:
In the games
A character named Roman also appears at the Seven Stars Restaurant in Pokémon Diamond, Pearl, and Platinum in a similar capacity as in the anime. However, the game Roman's Japanese name is リオ Rio and his only Pokémon are different, meaning Roman in the anime was at the most inspired by Roman in the game and is not the same character. In the games, Roman and Kylie's fathers are the owners of the restaurant.
This listing is of Roman's known Pokémon in the games: