Melanie was the character of the day in Bulbasaur and the Hidden Village. Her Japanese voice actor is Mako Hyōdō and her English voice actor is Tara Jayne. In this episode, Ash, Misty, and Brock were on their way to Vermilion City when Misty saw an Oddish. Misty tried to catch it when a Bulbasaur stopped her with a Vine Whip. Ash tried to catch the Bulbasaur, but the two Grass/Poison Pokémon escaped.

Ash and his friends tried to keep on traveling, but got caught in a series of traps, including a collapsing bridge, a pit, and a net. Brock fell into the river, but was saved by a beautiful girl named Melanie. She cared for Pokémon who have been abandoned in the forest. Melanie set the traps to try to deter people from catching the Pokémon she cared for.

Melanie allowed Ash and his friends to visit her Hidden Village of Pokémon if they promised not to catch any. Melanie explained that Bulbasaur had sworn to protect the other sick Pokémon. Bulbasaur continued to distrust Ash and Misty. Team Rocket attacked the village and tried to steal all the Pokémon, but Bulbasaur and Ash were able to defeat them.

Melanie insisted that Ash take Bulbasaur with him, since Bulbasaur wasn't able to grow any in the forest. Melanie thought that the Pokémon were getting too lazy with Bulbasaur to take care of them and they needed to be reintroduced into the wild. According to her, Bulbasaur would agree if Ash battled him; after winning that battle, Ash caught Bulbasaur, and everyone parted ways.