Ruby and Wally are walking through Petalburg Woods. As they admire the beautiful night sky, Ruby tries to recommend some wild Pokémon for Wally to catch. Wally notices a zigzag pattern floating in the air, so the two investigate it.
The pattern attacks, revealing it to be a wild Kecleon. Mumu manages to fend it off, causing the Kecleon to run away. Much to Ruby's horror, Wally decides that he wants to capture the Color Swap Pokémon and chases after it. They eventually reach Route 105, where Wally finds the Kecleon again and battles it with Rara.
Wally tries to capture it with a Poké Ball, only to fail, but he refuses to give up. Despite his failure, Wally begins to enjoy the battle, causing Rara's horns to glow in response to his emotions. In thanks for helping him, Wally gives Ruby a PokéNav as a gift. Wally reveals that he bought it without his parents knowing and intended to use it when he became a Trainer.
The Kecleon, tired from the attacks Rara used on it, decides to turn invisible to escape. Ruby and Wally pretend that they can't see it, but are able to actually see it because it can't turn its zigzag invisible. The Kecleon runs away, but Wally successfully manages to capture it in a Poké Ball. Overjoyed that he caught his first Pokémon, Wally begins crying tears of joy and expresses that he can move to Verdanturf Town without any regrets.
Suddenly, an earthquake begins tearing the ground apart, sending Ruby into the sea while Wally cries out unable to help. Later, Wally awakens at Verdanturf Town with Rara and panics about what had happened to Ruby. He tries to tell some adults, but Rara assures him that Ruby is still alive due to her being able to sense Ruby's emotions.