Movie Summary

Pikachu's Summer vaccation

Ash and his friends arrive at a Pokémon only park. They set all their Pokémon loose and, after Ash tells Pikachu to watch over Togepi, they enter for a day of fun and relaxation. Unfortunately, it's not going to turn out the way they had hoped.
Moments after they enter, Togepi starts to cry of hunger. Pikachu and Squirtle both try to cheer him up by making faces, but he cries on. Squirtle notices an apple in a tree, and Bulbasaur gets it down with Razor Leaf. The apple bounces to the ground and rolls to Psyduck's feet. Unknowing of Togepi's hunger, he eats it and walks off. Togepi continues to bawl. Bulbasaur sends out his Vines and lift him into the air. He gently waves Togepi in the air while quietly singing the first use of Bulbabye. Togepi calms down and goes to sleep.
A little bit later, four Pokémon come walking down the path. Snubbull, Marill, Cubone, and Raichu are all
talking rather loudly and Togepi looks as if he may wake up. Pikachu, Squirtle, and Bulbasaur confront the group and ask them to be quiet. They are less then willing to comply, and both groups get ticked off at each other. Pikachu tries to get them to set a good example for Togepi, but they don't listen. Suddenly, Pikachu realizes that Togepi has awakened and is now walking on a log crossing a rushing river. He goes after him, only to have the log start rolling with both him and Togepi on it. After a moment of rolling, Pikachu falls off into the water. He watches as the log goes off a cliff and into a large lake below, sending several water Pokémon into the air. He looks up at the edge of the cliff and is relieved to see that Togepi is safe and sound.
Back at the original scene, Squirtle and Snubbull have puffed out their chests. Squirtle topples over onto his shell and the other Pokémon laugh. At this, Squirtle gets even more ticked off and challenges Marill, a water type Pokémon, to a race. Soon afterwards, they are both standing at the edge of the lake, the other side as the finish line. Pikachu waves his hand to start the race, and an Electrode uses Explosion, knocking over all the Pokémon nearby. Squirtle and Marill are fairly evenly matched until Marill takes a deep breath and dives under the water, pulling ahead. As he can't see where he's going, he slams into a Starmie, who Water Guns him to one side of the lake.
Squirtle continues to swim along, confident that he'll win. Suddenly, it occurs to him that he's going backwards and he realizes that he's on the back of a Goldeen, who's rapidly taking him back towards the starting line. He jumps off and tries his hardest to get to the other side, but he's too late and Marill wins.
The two groups of Pokémon confront each other once again, and Raichu starts sending sparks out. Togepi is frightened and Pikachu protects him, only to be shocked himself. At this, Pikachu gets angry and he walks up to Raichu. Pressing their cheeks together, they start to run quite fast up a mountain, down the mountain, up a waterfall, through a field (where they blast Team Rocket's Pokémon into the air), along another path (where they blast a Hitmonchan and Hitmonlee into the air), and over Charizard's tail. Charizard gets angry and chases after them, getting in head and using his wings to Gust them away. They land onto a Snorlax's stomach and bounce off, only to have the Snorlax roll on top of him. After squeezing out from under Snorlax's huge body, Pikachu, Raichu, and the rest of the Pokémon face off once again. Charizard, who had been flying about, swoops down over them and frightening them. He doesn't watch where he goes though, and crashes through a jungle gym type thing and a couple of piles of tires, ultimately getting his head wedged into a small pipe. He thrashes about for a bit, yelling out. Meowth, who is resting with Arbok and Weezing directly above, gets annoyed and leans over the ledge to yell down. At this moment, Charizard lets out a burst of flames, scorching Meowth's face.
Pikachu, Bulbasaur, Squirtle, Togepi, Psyduck, Geodude, Pidgeotto, Zubat, Vulpix, and Onix all join in together pulling on a rope tied to Charizard's leg while he continues to let blast after blast of fire through the pipe. They pull and pull, but can't get him free. Snubbull, Marill, Raichu, and Cubone stand nearby, laughing. Charizard shifts his leg, and all the Pokémon fly forward. Charizard gets worried that he may never get out, and starts to sob. Pikachu walks over to where the other Pokémon are standing and asks them to help. Snubbull, Marill, and Raichu agree to help, but Cubone, caring only for himself, refuses. All the Pokémon, with their new helpers, continue to pull at Charizard's leg as Cubone looks on. Soon, seeing how upset Charizard is and how the others almost have him out but not quite, he joins in at the head of the team. After another few moments of pulling, Charizard's head pops out, and they all fly backward. Charizard, happy to be free, flies up into the air with Psyduck still holding onto the rope. Meowth, having been woken up once again, lights a bomb to throw down at the Pokémon below. Seeing a shadow, he looks up just in time to see Charizard land on him. Psyduck bounces off of Charizard's stomach and the bomb explodes beneath the large Pokémon. He moves, and Meowth emerges from the hole long enough to say that he'll sleep right there, slipping back down again.

All of the Pokémon, relieved to have Charizard out, work together to help rebuild the things he broke. Afterwards, they play in the sand, water, and on swings and slides together, showing how much can be done and how much fun Pokémon (and people for that matter) can have when they set aside their differences. Later that afternoon, all the Pokémon sit and watch the sunset. They hear Ash, Misty, and Brock calling for them and set off. Pikachu lags behind long enough to thank their new friends, then dashes forward into Ash's arms. "Did you have fun?" he asks. Pikachu just smiles and says "Pika!"