While watering some of Goh's Grass-type Pokémon at Cerise Park's flower field, Ash and Goh witness Goh's Flabébé having a race with each other and evolving into Floette as a result. Goh is happy to see this, until he notices that the White Flower Flabébé is not amongst them. When he and Ash find her, it turns out one of her flower's petals has fallen off, preventing her from flying properly. To find a new flower for her, they decide to travel to Kalos, where Goh had caught Flabébé.
Arriving in Shalour City, Ash and Goh start looking for a white flower. Since Flabébé's flower is too damaged to fly well, Goh puts it in a glass jar, while Flabébé rides on Goh's head and clings to his hair as she leads them to the spot where she had originally gotten her flower from. Unfortunately, upon finding the spot where the flower used to grow, they discover that it is now covered by a big rock. Any attempts to find more white flowers nearby fail, so they retreat to the local Pokémon Center for the night. Flabébé is feeling dejected, but when Grookey accidentally dumps some Honey that Goh had tried to offer for Flabébé on his hair and starts reshaping the hair into various shapes, Flabébé is cheered up again. Before going to bed, Ash and Goh call Professor Cerise, who promises to call back to them if he finds out anything useful. As the night falls, Goh wakes up to Flabébé tugging on his hair, and agrees to go on a nighttime walk with her.
Ash and Goh spend the next day looking for a new flower for Flabébé, but none of the numerous white flowers they find is good enough for her. They set up a camp for the night in a forest, and Goh promises to Flabébé that he won't mind her staying on his head until they find a new flower for her, no matter how long it takes. When Grookey accidentally wakes up Goh in the middle of the night, he notices that Flabébé and her damaged flower are missing. He ends up finding Flabébé nearby, desperately trying to fly with the flower, but failing each time. Goh realizes that while he might not have a problem with Flabébé staying on his head as long as necessary, Flabébé herself is desperate to find a new flower, so he promises to find one the next day.
The next morning, Ash and Goh receive a call from Professor Cerise, who directs them to a plant researcher who knows about Flabébé's white flowers. They arrive at the researcher's home, where her Orange Flower Florges notices Goh's Flabébé missing her flower, and takes her with her to the researcher's garden to demonstrate her Grassy Terrain, which makes the flowers in the garden bloom. The researcher explains that Flabébé draw their power from flowers, Floette tend to flowers, and Florges devote their lives to protecting flower gardens. She also reveals that her Florges also once lost her orange flower, and finding a new one hadn't been easy, which is why she sympathized with Goh's Flabébé. Goh says he wants to find a white flower for Flabébé, and the researcher directs him and Ash to the mountains in the northwest, where a researcher friend of hers had spotted a cluster of them.
While traveling to the mountains by bus, Goh notices Flabébé trying to mimic the gestures Florges had made while using Grassy Terrain, and understands that she wants to have her own flower garden too someday. In the mountains, Ash and Goh manage to locate a cluster of flower buds, but they're pink, so they search elsewhere. However, as the night begins to fall, they've not found anything. Suddenly, Flabébé starts pulling on Goh's hair, signaling for him to turn back. They return to the pink buds they found earlier, which end up blooming into white flowers as the moon shines on them. Flabébé chooses one of them, and is finally able to fly again. Ash and Goh then notice another Flabébé, which doesn't have a flower yet, meaning that she's choosing her first flower now.
As the wild Flabébé flies away with her new flower, only one white flower remains in the cluster, and Goh's Flabébé is worried. She starts performing the Grassy Terrain pose again, during which she evolves into Floette. Thanks to her new powers, Floette is now able to use Grassy Terrain, creating two new buds in place of the flowers that were just picked. Still, however, she's worried about the future of the white flowers. Recalling the researcher's words about the role that each member of the Flabébé line serves and his own realization about Flabébé wanting her own flower garden, Goh understands that Floette wants to stay here to protect the flowers, which she confirms.
Ash and Goh move to a cliffside and prepare to say goodbye to Floette. Grookey starts crying, as does Floette, but Goh says they have to say goodbye so that Floette can do her best. He promises to Floette that they'll come back someday to see the garden of white flowers she's grown. As the sun rises over the mountains, Goh bids farewell to his Floette, who flies off into the distance to go fulfill her dream.