She and her younger sister Lyn were resting at the same Pokémon Center as Ash and his friends were, when Lyn's bag containing the Pichu she cares for got accidentally switched with Bonnie's bag containing Dedenne. As Lena and Lyn left and were walking down the street, Lyn noticed Dedenne was in her bag instead of Pichu. While Lena was talking with a friend, Lyn ran off to find Pichu. As she ended her conversation, Lena found out Lyn was gone, much to her worries.
Meanwhile, Ash and and his friends were looking for Dedenne. Clemont came with the idea to use one of his inventions to lure Dedenne to them. The invention exploded however, but the explosion was noticed by Lena, who quickly rushed to the scene. There she found the group, and Pichu, much to her relief. The group then explained the situation to Lena, and Lena told them she suspected Dedenne was with her sister Lyn. Now searching for Lyn and Dedenne, the group and Lena eventually found them in a grape orchard, about to be attacked by wild Beedrill. Ash's Pikachu saved them in the nick of time, and Lena was reunited with Lyn. Then the group and Lyn and Lena decided to have dinner together.