"Pikachu's Summer Vacation" is a short anime feature that centers around Pikachu and other Pokémon as they enjoy a summer break at a Pokémon-exclusive resort. The narrative unfolds during a lively festival organized for the Pokémon, where they engage in various activities and competitions. The main focus is on Pikachu and its interactions with other Pokémon, including Bulbasaur, Squirtle, and Charizard, as well as newcomers like Snorlax and a group of mischievous Marill.

The story begins with the Pokémon arriving at the resort, where they are free to relax and play without their trainers. The festival includes games, races, and other events designed to showcase the unique abilities and personalities of the Pokémon. Pikachu quickly becomes a central figure, participating in a race and forming bonds with other Pokémon. The Marill, however, cause trouble by disrupting the events and creating chaos, leading to a series of comedic and lighthearted confrontations.

As the festival progresses, the Pokémon work together to overcome the challenges posed by the Marill, ultimately fostering a sense of camaraderie and teamwork. The climax involves a grand race where Pikachu and its friends compete against the Marill, highlighting their determination and sportsmanship. The story concludes with the Pokémon celebrating their summer adventure, reflecting on the fun and friendships they have built.

The narrative emphasizes the playful and carefree nature of the Pokémon world, focusing on their interactions and personalities rather than complex plotlines. The characters are portrayed in a manner consistent with their established traits, with Pikachu serving as a cheerful and resourceful protagonist. The short runtime and episodic structure make it a lighthearted addition to the Pokémon franchise, appealing to fans of the series and younger audiences.