From Bulbapedia, the community-driven Pokémon encyclopedia.
<i>Ash and his friends have reached Shelter Town, a snow-covered town near Snowpoint City, and they’re taking a break at the Pokémon Center. When Dawn brings out her Buneary, it attracts attention from Marilyn, a Trainer who loves cute Pokémon more than anything else. Marilyn thinks Piplup isn’t cute at all, but she wants to battle Buneary; Dawn agrees, eager to avenge Piplup’s pride. As it turns out, Marilyn only wants to watch her Cherubi act dramatic. Brock has to prod her to actually battle, but when she does battle, she wins!