When Satoshi is about to leave Pallet Town, Satoshi's mom gives him a present, a new pair of gloves. Then Shigeru's sister comes from outside and gives him a Town Map even though Shigeru told her not to give Satoshi the map, but she decided to give the map to him anyway. All packed up, Satoshi leaves for Viridian City.
While in Viridian City, Satoshi is amazed at how big it is. He then sees the city's Gym and remembers how he must get all eight Gym Badges to get in the Pokémon League and battle the Elite Four. Satoshi tries to enter the Gym, but a little boy in a boy scout's uniform tells him that the Gym is closed. So Satoshi is told to go through Viridian Forest to get to the next nearest Gym. So Satoshi goes through the forest, eventually finding a Pikachu chasing an acorn. The Pikachu, after seeing Satoshi, leaps behind a bush and hides. Satoshi picks up an acorn to convince he's friendly, which brings Pikachu out of hiding and it decides decides to join Satoshi on his journey.
Satoshi finally arrives in Pewter City and sees a Fisherman and a Camper fighting. Then, a camper shows Satoshi the city's Fossil exhibit while telling him of Brock, the Gym Leader of Pewter City.
The Camper takes Satoshi to the Gym. While in the Gym, Satoshi challenges Brock to a battle. He brings out Onix, and Satoshi sends Charmander. Brock orders Onix to attack, Charmander dodges Onix's first attack. Then Satoshi gets an idea, Charmander is told to chop the horn-like part of Onix's head off and Onix falls after hit. Satoshi wins the battle receives the Boulder Badge and waves good-bye to the Camper and Brock as he leaves for his next challenge.