Kay was one of the Pokémon Performers, who voiced their Pokémon. When she met Raichu, him went to hug her, but Anne was scared by the electric jolt and threw him away. Raichu disobeyed her orders, so Ash was asked to show some pointers with his bond with Pikachu. After Team Rocket attacked, Kay trusted Raichu, who began obeying her and defeated Team Rocket, while also performing at the shows.
Raichu disobeyed Kay as Kay was scared of it, but Kay began trusting it, enough for Raichu to listen to her and obey.