The game begins with the player being given a device (the VRU) by Professor Oak which allows them to communicate with Pokemon, they then use the device to communicate with and befriend a wild Pikachu. The player then goes on a series of daily adventures with Pikachu such as fishing, gathering food in a forest for a feast with other wild Pokemon, or just exploring a large field of flowers. At the end of each day the player receives "Pika Points" from Pikachu, a currency which can be used to buy items, such as new toys, from Abra. After 1 year (365 days) worth of days, Oak again appears, telling the player they must release Pikachu (who has come to live in the player's home) as he is a wild Pokemon. After a series of goodbyes, Pikachu is left in the forest as the player returns home. However, the next day, Pikachu comes back; now living in the forest, but returning to adventure with the player each day.
If the player of Hey You, Pikachu says "Playstation," Pikachu will become angry at the player.
Hey You, Pikachu was the only game released in the US to use the VRU.