Hazel cries to Pikachu and Clefairy that she had a fight with Almond after he had blamed her for scaring off a Pinsir he was trying to catch. She is especially upset because it is the day before Almond's birthday, and she had planned to throw a party for him and gift him a towel she had made. Seeing Hazel so distraught, Pikachu and Clefairy take it upon themselves to fix things between her and Almond.
Pikachu and Clefairy begin making preparations for the party, but to their surprise, Jigglypuff wants to join them. When Jigglypuff wants to make the cake, Clefairy and Pikachu both nervously suggest it should gather the flowers for a bouquet instead, taking into consideration what happened the last time Jigglypuff made a cake.
The next morning, before Hazel leaves for school, she gives Pikachu some origami paper it had asked for. Pikachu then takes it to a Scyther, who uses its blades to slice the paper into smaller pieces. As Clefairy puts the finishing touches on the cake, Pikachu uses the sliced paper to weave colorful chains to be used as decorations. Meanwhile, as Jigglypuff collects some flowers, it spots a giant blossom on the side of a cliff. Pikachu and Clefairy arrive just in time to see Jigglypuff break the stem of the flower. It and Jigglypuff come crashing down, landing on the two Pokémon.
Later, when everything is all set for the party, Hazel comes home from school. Shocked to see what the Pokémon have done, she runs off to fetch Almond for the party. She and Almond both apologize to each other, then celebrate his birthday. Hazel gives Almond the towel she made, and Jigglypuff presents its bouquet. To everyone's confusion, an Oddish pops out from the flowers. It suddenly evolves into a Gloom, then puffs out a noxious odor. All of the party guests fall unconscious, and Gloom helps itself to a slice of cake.