As this story begins, our heroes are sitting in the Pokémon Center playing when Ash gets a phone call from Professor Oak on the PC phone. Professor Oak appears on the screen and so does Ash's Muk, the Pokémon Professor very displeased with Ash's Muk as it has climbed all over him and spoiling his new lab coat. Professor Oak informs Ash that his Pokédex is now upgradeable and tells Ash of how he can do so. Ash follows the directions and places his Pokédex into the small slot on the computer. They go back to a table and talk about the Pokémon that they wish would hatch out of the mysterious egg that Ash found back at the Pokémon Fossil Canyon. Naturally they all say their favorite Pokémon, Misty choosing a Template:Type2 and Brock choosing a Template:Type2.
After that, they leave the Pokémon Center and head outside where they find Team Rocket posing as egg sellers. They have a whole basketful of eggs, just like Ash's mysterious egg. Team Rocket tries to talk them into trading or buying one of their eggs and when they politely refuse Jessie and James resort to throwing all of their fake eggs in the air. The real egg, that Brock was holding, gets taken when there is a mix-up with all the eggs.
Team Rocket run out of site and escape with the real egg! Ash, Misty and Brock are stuck with a fake. Whilst in Team Rockets little hiding shack Meowth takes care of the egg. Whilst it is in his possession, the egg gets its best attention ever. Meowth sleeps with it, sings with it and even eats with it.
The three young adventurers follow a trail of broken red blue and green eggs until they reach the shack in which Team Rocket are hiding. They decide to burst in, even though it may be dangerous, and get the egg back.
They all quickly bust into the shack but unfortunately James is quick to react. He sends out Weezing who gives a Poison Gas attack, making Ash and others cough and gasp for breath. Ash sends out Pidgeotto and tells it to use a Gust attack to clear away the Poison Gas. They take a lunge for the little white egg. The egg goes up and down much like in a game of football! Through much controversy Pikachu ends up with the egg and gives the egg back to Ash, at that moment the egg begins to break open, beginning to hatch.
Misty, enthralled with what was going on, jumps in pushes everyone out of the way to get a closer look and the newly hatched Pokémon. When she does the egg hatches, revealing a new unidentified Pokémon. Ash and others are all surprised, especially Team Rocket who instantly want to steal it. Ash points his newly updated Pokédex at the Pokémon, identifying it as a Togepi.
Togepi, unlike other Pokémon, will not just like anybody, to Ash's and Brock's disappointment. It chooses Misty! As Misty is the first thing that the Pokémon saw, it thinks that Misty is its mother.
This newly hatched Pokémon causes quite a fuss among the group. Ash feels that he should have it because he found it; Brock feels it should be his because he cared for it before Meowth; Meowth wants it because he looked after it before it hatched, Jessie and James both just want it! Meowth says to them that they didn't do anything to help in Togepi's growth. Misty feels she should have it, as Togepi likes her best. They all decide to have a Pokémon tournament to decide who should have it. Meowth panics because he has no Pokémon and goes and asks Jessie and James for theirs. They refuse as he didn't let them participate, Meowth then remembers that he is a Pokémon and decides to battle for himself. After the draw ends up between Misty and Ash, the first battle since Cerulean City. Of course everybody's favorite trainer, Ash, wins, but because Misty was the first thing that Togepi, saw she gets to keep it.