From Bulbapedia, the community-driven Pokémon encyclopedia.
The Seven Stars Restaurant (Japanese: レストランななつぼし Restaurant Seven Stars) is an indoor eatery located in Sinnoh on Valor Lakefront as part of the Hotel Grand Lake.
In the games
In the restaurant, the player may battle the customers; this is considered proper etiquette in the restaurant. They are Double Battles and the Pokémon range in level from 20-23 in Diamond and Pearl, or 24-31 in Platinum. The battles are only held from 9 a.m. to 11 p.m. Five of the nine possible pairs of Trainers are randomly chosen every day.
Trainers
Diamond and Pearl
Platinum
In the anime
Seven Stars Restaurant in the anime
The Seven Stars Restaurant was featured prominently in A Full Course Tag Battle!. The restaurant had a battlefield in which a Trainer wishing to have a meal has to battle the owners of the restaurant, Roman and Kylie. Trainers winning against Roman and Kylie are presented with a free seven course meal.
Ash, Dawn, Brock, and May visited the restaurant with reservations set by May. Upon arriving, they realized that they had to battle Roman and Kylie. Ash and Brock defeated them; however, during May and Dawn's battle, Team Rocket broke in and stole all of the food. After retrieving the food and defeating Team Rocket, the group was offered a free meal, despite not completing the battle. However, May and Dawn battled Kylie and Roman while waiting for the meal to be ready and defeated them, securing the free meal.
Trivia